WO2017122207A1 - Modified polyamide membranes - Google Patents

Modified polyamide membranes Download PDF

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Publication number
WO2017122207A1
WO2017122207A1 PCT/IL2017/050041 IL2017050041W WO2017122207A1 WO 2017122207 A1 WO2017122207 A1 WO 2017122207A1 IL 2017050041 W IL2017050041 W IL 2017050041W WO 2017122207 A1 WO2017122207 A1 WO 2017122207A1
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Prior art keywords
composite membrane
water permeability
water
amine
bar
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PCT/IL2017/050041
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French (fr)
Inventor
Viatcheslav Freger
Shiran SHULTZ
Raphael Semiat
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Technion Research & Development Foundation Limited
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Publication of WO2017122207A1 publication Critical patent/WO2017122207A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
    • B01D67/0002—Organic membrane manufacture
    • B01D67/0006—Organic membrane manufacture by chemical reactions
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
    • B01D67/0081—After-treatment of organic or inorganic membranes
    • B01D67/0093—Chemical modification
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
    • B01D67/0081—After-treatment of organic or inorganic membranes
    • B01D67/0093—Chemical modification
    • B01D67/00931—Chemical modification by introduction of specific groups after membrane formation, e.g. by grafting
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
    • B01D69/02—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor characterised by their properties
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
    • B01D69/12—Composite membranes; Ultra-thin membranes
    • B01D69/125—In situ manufacturing by polymerisation, polycondensation, cross-linking or chemical reaction
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
    • B01D69/12—Composite membranes; Ultra-thin membranes
    • B01D69/125—In situ manufacturing by polymerisation, polycondensation, cross-linking or chemical reaction
    • B01D69/1251—In situ manufacturing by polymerisation, polycondensation, cross-linking or chemical reaction by interfacial polymerisation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/06—Organic material
    • B01D71/56—Polyamides, e.g. polyester-amides
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G69/00—Macromolecular compounds obtained by reactions forming a carboxylic amide link in the main chain of the macromolecule
    • C08G69/02—Polyamides derived from amino-carboxylic acids or from polyamines and polycarboxylic acids
    • C08G69/26—Polyamides derived from amino-carboxylic acids or from polyamines and polycarboxylic acids derived from polyamines and polycarboxylic acids
    • C08G69/32—Polyamides derived from amino-carboxylic acids or from polyamines and polycarboxylic acids derived from polyamines and polycarboxylic acids from aromatic diamines and aromatic dicarboxylic acids with both amino and carboxylic groups aromatically bound
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G69/00—Macromolecular compounds obtained by reactions forming a carboxylic amide link in the main chain of the macromolecule
    • C08G69/48—Polymers modified by chemical after-treatment
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L77/00—Compositions of polyamides obtained by reactions forming a carboxylic amide link in the main chain; Compositions of derivatives of such polymers
    • C08L77/10—Polyamides derived from aromatically bound amino and carboxyl groups of amino-carboxylic acids or of polyamines and polycarboxylic acids
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2323/00—Details relating to membrane preparation
    • B01D2323/15—Use of additives
    • B01D2323/218—Additive materials
    • B01D2323/2182—Organic additives
    • B01D2323/21834—Amines
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2325/00—Details relating to properties of membranes
    • B01D2325/20—Specific permeability or cut-off range

Definitions

  • the present invention in some embodiments thereof, relates to membranes for reverse osmosis, and more particularly, but not exclusively, to membranes which efficiently remove boron from water, to articles containing same and to uses thereof.
  • Synthetic membranes for separation are used in many industrial applications, including water treatment. Membranes are used for filtration of potable water, treatment of industrial and municipal waste water, and for desalination of brackish water and seawater.
  • RO membrane desalination has become one of the main desalination techniques, estimated as providing 44 % of the total volume of desalinated water in the world, and its use is expected to grow in the coming years [Greenlee et al., Water Res 2009, 43:2317-2348].
  • RO is a pressure-driven process whereby a semipermeable membrane (i.e., RO membrane) rejects dissolved constituents in the feeding water but allows water to pass through.
  • RO technology is greatly dependent on the development of RO membranes, as the membrane plays a key role in technological and economic efficiency of the RO process [Loeb & Sourirajan, Adv Chemistry 1962, 38:117-132].
  • Thin-film composite (TFC) membranes with a polyamide top layer are the most common type of RO membranes used nowadays. These membranes are composed of three distinct layers on top of each other.
  • the top layer is a thin, dense, non-porous aromatic or semi-aromatic polyamide active layer, is typically 20 to 200 nm thick and provides the separation selectivity [Petersen, J Membr Sci 1993, 83:81-150].
  • the top layer is typically deposited on a porous layer of polyethersulfone or polysulfone which is on top of a non-woven fabric support sheet.
  • the polyamide top layer is typically prepared by interfacial polymerization of an aromatic triacid and diamine.
  • the top layer thus typically contains some unreacted, mainly acidic carboxylic acid, groups within the membrane and on the surface.
  • the TFC aromatic polyamide membrane exhibits superior water flux and salt rejection, resistance to pressure compaction, wider operating temperature range and pH range, and higher stability to biological attack [Li & Wang, Materials Chem 2010, 20:4551-4566].
  • a major limitation of such membranes is the relatively poor removal of small uncharged molecules such as boric acid.
  • Seawater contains boron (in the form of boric acid) at concentrations of 4-7 ppm. Although its toxicity to humans is low, the World Health Organization recommended guideline for maximum boron concentration in potable water is 0.5 ppm [Bernstein et al., Environ Sci Technol 2011, 45:3613-3620]. Furthermore, although boric acid is an essential micronutrient for plants, it becomes toxic to plants at concentrations above 0.5- 1 ppm (depending on their boron tolerance) [Tang et al., J Membr Sci 2007, 290:86-94]. Therefore, the recommended maximal boron concentration for desalinated water which may be used for irrigation is 0.3-0.5 ppm.
  • Boric acid is a weak acid with pKai of about 8.6-9.2 in seawater [Hansson, Deep-Sea Res 1973, 20:461-478].
  • Uncharged boric acid has a molecular diameter of 2.75 A, and its Stokes radius is only about 1.55 A, as calculated from the diffusion coefficient 1.41 x 10 "9 m 2 /s in water at pH 7 [Park & Lee, Chem Eng Data 1994, 39:891-894].
  • boric acid is significantly smaller than hydrated sodium (3.58 A) and chloride (3.32 A) ions, rendering removal of boron considerably more difficult than removal of sodium chloride.
  • Boron removal can be improved by various pre- and post-treatment techniques [Xu & Jiang,. Ind Eng Chem Res 2008, 47: 16-24] and by double -pass RO. Faigon & Hefer [Desalination 2008, 223:10-16] describe a four-stage process for reducing boron concentration. However, additional treatment steps increase the energy consumption and water cost substantially.
  • U.S. Patent No. 6,296,773 describes a process for reducing boron and fluoride ion content of water by using magnesium to precipitate boron and fluoride.
  • U.S. Patent No. 8,236,180 describes a method of removing boron from water by using an amide derivative under alkaline conditions to cause adsorption of boron to the amide derivative, followed by addition of a cation to cause aggregation of the amide body.
  • U.S. Patent No. 7,279,097 describes a composite semipermeable membrane having a high rejection performance for salt and non-dissociative substances such as boric acid, wherein a monofunetional amine binds to and/or adsorbs to the inside and/or surface of the membrane, and/or wherein an aliphatic acyl group binds to the inside and/or surface of a separating functional layer.
  • Bernstein et al. discusses the contribution of hydrophobicity and steric exclusion (e.g., smaller pore size) towards rejection of boron, and describes modification of low pressure RO membranes by graft polymerization of glycidyl methacrylate, resulting in a membrane with a relatively high permeability characteristic of brackish water RO, but with removal of boric acid and salt superior to those of most commercial brackish water RO membranes.
  • U.S. Patent No. 5,755,964 describes a one-step process for enhancing the flux of a composite reverse osmosis or nanofiltration membrane while substantially maintaining the NaCl rejection rate, in which the discriminating layer is contacted with ammonia or certain alkylamines.
  • a water permeable composite membrane comprising a thin film layer on a porous substrate, the thin film comprising a polymer and amine-containing compound associated with the polymer, the amine-containing compound comprising at least one aliphatic hydrocarbon moiety attached to an amine group.
  • a process for preparing the water permeable composite membrane described herein comprising contacting a thin film layer comprising the polymer with the amine- containing compound.
  • a reverse osmosis apparatus comprising the water permeable composite membrane described herein.
  • a method of treating water comprising passing water with solutes through the water permeable composite membrane described herein, thereby treating the water.
  • the polymer comprises a poly amide.
  • the aliphatic hydrocarbon moiety is from 1 to 30 carbon atoms in length, being saturated or unsaturated, and substituted or unsubstituted.
  • the aliphatic hydrocarbon moiety is at least 3 carbon atoms in length.
  • the aliphatic hydrocarbon moiety contains at least 8 carbon atoms.
  • the amine-containing compound has the general formula:
  • Ri is the aliphatic hydrocarbon moiety
  • R 2 and R 3 are each independently selected from the group consisting of hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, and a heteroalicyclic, or, alternatively, one or both of R 2 and R 3 is independently a covalent bond linking the amine-containing compound to the polymer or a group participating in a covalent bond linking the amine- containing compound to the polymer.
  • the amine-containing compound is associated with the polymer via an amide bond to the polymer.
  • at least one of R 2 and R 3 is a covalent bond linking the amine-containing compound to the polymer or a group participating in a covalent bond linking the amine-containing compound to the polymer.
  • R 2 and/or R 3 is an amide bond with a carboxylic group in the polymer.
  • R 2 is hydrogen and R 3 is an amide bond described herein.
  • the amine-containing compound is associated with the polymer via non-covalent interactions.
  • R 2 and R 3 are each independently selected from the group consisting of hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, and a heteroalicyclic.
  • R 2 and R 3 are each hydrogen.
  • the aliphatic hydrocarbon moiety is at least 5 carbon atoms in length.
  • Ri is at least 8 carbon atoms in length.
  • Ri consists of a linear aliphatic hydrocarbon moiety which is unsubstituted or is substituted by one or more substituents selected from the group consisting of alkyl, alkenyl, alkynyl, cycloalkyl, heteroalicyclic, halo, hydroxy, alkoxy, thiohydroxy, thioalkoxy, sulfinyl, sulfonyl, cyano, nitro, azide, phosphonyl, phosphinyl, oxo, carbonyl, thiocarbonyl, urea, thiourea, O-carbamyl, N-carbamyl, O-thiocarbamyl, N-thiocarbamyl, C-amido, N-amido, C- carboxy, O-carboxy, sulfonamido, and amino.
  • substituents selected from the group consisting of alkyl, alkenyl, alkynyl, cycloal
  • each of the one or more substituents is no more than 3 atoms in length.
  • the one or more substituents are each independently selected from the group consisting of methyl, halo, hydroxy, thiohydroxy, oxo, and -NH 2 .
  • the one or more substituents are selected from the group consisting of alkyl, alkenyl, alkynyl, cycloalkyl, and halo.
  • the linear aliphatic hydrocarbon moiety is substituted by no more than two substituents.
  • the linear aliphatic hydrocarbon moiety is substituted by no more than one substituent.
  • the linear aliphatic hydrocarbon moiety comprises no more than one substituent attached to each carbon atom in the linear aliphatic hydrocarbon moiety.
  • a LogP of the amine- containing compound is at least 0.2.
  • a LogP of the amine- containing compound is at least 1.0.
  • a LogP of the amine- containing compound is no more than 6.0.
  • a minimum projection area of the amine-containing compound is no more than 30 A 2 .
  • a minimum projection area of the amine-containing compound is at least 18 A 2 .
  • a boron passage rate of the composite membrane is less than 80 % of a boron passage rate of a corresponding composite membrane without the amine-containing compound covalently and/or non- covalently bound to the polymer, wherein the boron passage rate is determined using an aqueous solution of boric acid and NaCl with 32,000 ppm NaCl and 5 ppm boron, at pH 7, and at a feed pressure of 55 bar.
  • a water permeability of the composite membrane is at least 20 % of a water permeability of a corresponding composite membrane without the amine-containing compound covalently and/or non- covalently bound to the polymer, wherein the water permeability is determined using an aqueous solution of boric acid and NaCl with 32,000 ppm NaCl and 5 ppm boron, at pH 7, and at a feed pressure of 55 bar.
  • a boron passage rate of the composite membrane is less than 20 %, wherein the boron passage rate is determined using an aqueous solution of boric acid and NaCl with 32,000 ppm NaCl and 5 ppm boron, at pH 7, and at a feed pressure of 55 bar.
  • a water permeability of the composite membrane is at least 0.2 liters per square meter per bar per hour (l-m ⁇ 2 -bar ⁇ ⁇ hour "1 ), wherein the water permeability is determined using an aqueous solution of boric acid and NaCl with 32,000 ppm NaCl and 5 ppm boron, at pH 7, and at a feed pressure of 55 bar.
  • a ratio of a boron passage rate to water permeability of the composite membrane is less than 90 % of a ratio of a boron passage rate to water permeability of a corresponding composite membrane without the amine-containing compound covalently and/or non-covalently bound to the polymer, wherein the boron passage rate and the water permeability are determined using an aqueous solution of boric acid and NaCl with 32,000 ppm NaCl and 5 ppm boron, at pH 7, and at a feed pressure of 55 bar.
  • a ratio of a boron passage rate to water permeability of the composite membrane is less than 30 % boron passage rate per 1.0 liter per square meter per bar per hour water permeability (30 % per l-m "2 -bar " ⁇ hour "1 ), wherein the boron passage rate and the water permeability are determined using an aqueous solution of boric acid and NaCl with 32,000 ppm NaCl and 5 ppm boron, at pH 7, and at a feed pressure of 55 bar.
  • the polymer comprises free carboxylic acid groups, and the process described herein further comprising contacting the thin film layer with an activator of carboxylic acid groups, the activator being selected as being capable of forming an amide bond between carboxylic acid groups and amine groups.
  • a ratio of free carboxylic acid groups to amide groups in the polymer prior to contacting the thin film layer with the activator of carboxylic acid groups is in a range of from 1:50 to 1: 1 (free carboxylic acid: amide).
  • the contacting described herein is effected using a solution of the amine-containing compound, wherein a concentration of the amine-containing compound in the solution is selected such that a water permeability of the composite membrane is at least 0.2 liters per square meter per bar per hour (l-m ⁇ bar ⁇ hour 1 ), wherein the water permeability is determined using an aqueous solution of boric acid and NaCl with 32,000 ppm NaCl and 5 ppm boron, at pH 7, and at a feed pressure of 55 bar.
  • the thin film layer is degraded following use thereof to treat water, the process described herein being for at least partially restoring the degraded thin film layer.
  • the thin film layer is degraded following use thereof at a pH of at least 8.
  • treating the water as described herein comprises reducing a concentration of boron in the water to less than 0.5 ppm.
  • passing the water through the water permeable composite membrane as described herein is effected no more than once.
  • the water with solutes has a pH of at least 8.
  • the method comprises:
  • FIG. 1 is a depiction of the structure of a polyamide in the top layer of a commercially available thin-film composite membrane (free amine group and free carboxylic acid group are circled).
  • FIG. 2 presents a bar graph showing water flux through polyamide membranes treated with 15.64 mM propylamine, butylamine, 2-methyl-butylamine or tert- octylamine, or with 1.04 mM amylamine, hexylamine, decylamine or dodecylamine, following activation of the membrane with EDC (testing conditions: 55 bar).
  • FIG. 3 presents a bar graph showing the boron passage of polyamide membranes treated with propylamine, butylamine, 2-methyl-butylamine, amylamine, hexylamine, tert-octylamine, decylamine or dodecylamine, following activation of the membrane with EDC (testing conditions: 5 ppm boron, 32,000 ppm NaCl, pressure 55 bar; each bar represents average of at least 4 results).
  • FIG. 4 presents a graph showing boron rejection (defined as 100 % minus boron passage in %) of polyamide membranes treated with an amine containing compound (propylamine, butylamine, 2-methyl-butylamine, amylamine, hexylamine, tert- octylamine, decylamine or dodecylamine) as a function of the minimum projection area (MPA) of the amine-containing compound (testing conditions: 5 ppm boron, 32,000 ppm NaCl, pressure 55 bar; data point for tert-octylamine is circled).
  • an amine containing compound propylamine, butylamine, 2-methyl-butylamine, amylamine, hexylamine, tert- octylamine, decylamine or dodecylamine
  • FIG. 5 presents an ATR-FTIR (attenuated total reflectance Fourier transform infra-red) spectrum of a pristine polyamide membrane (dashed line) and a polyamide membrane modified by amidation with EDC and propylamine (dotted line) or dodecylamine (solid line) (aliphatic C-H stretching bands are in 2800-3000 cm "1 region).
  • ATR-FTIR attenuated total reflectance Fourier transform infra-red
  • FIG. 6 presents a bar graph showing the boron passage of SWC4B polyamide membranes before and after modification of the membrane with amylamine, hexylamine, decylamine or dodecylamine (testing conditions: 5 ppm boron, 32,000 ppm NaCl, pressure 55 bar; each bar represents average of at least 4 results).
  • FIG. 7 presents a graph showing boron passage of polyamide membranes as a function of water permeability of the membrane in a dead-end cell, for unmodified SWC5max and SWC4B polyamide membranes, SWC5max membranes treated with carbodiimide and propylamine (C3 circle), butylamine (C4 circle), 2-methyl-butylamine (C5* circle), amylamine (C5 circle), hexylamine (C6 circle) or tert-octylamine (C8* circle), and SWC4B membranes treated with carbodiimide and decylamine (CIO circle) or dodecylamine (C12 circle), or treated with amylamine (C-5 triangle), hexylamine (C6 triangle), decylamine (CIO triangle) or dodecylamine (C-12 triangle) without a carbodiimide (testing conditions: 5 ppm boron, 32,000 ppm NaCl, pressure 55 bar; each
  • FIG. 8 is a scheme depicting an apparatus for treating and testing a multi- membrane element according to some embodiments of the invention; the apparatus comprises a feed tank, a multi-membrane element mounted in a stainless steel pressure vessel (M-l), a high pressure pump with an auxiliary feed pump, a feed pressure gauge (PI-1), a control valve with a pressure gauge located in the concentrate line (PI-2), a heat exchanger (HE-1) equipped with a thermometer configured controlling and monitoring water temperature, and a tank drainage valve (D-l).
  • M-l stainless steel pressure vessel
  • PI-1 feed pressure gauge
  • HE-1 control valve with a pressure gauge located in the concentrate line
  • D-l tank drainage valve
  • FIGs. 9A and 9B present graphs showing boron passage and water flux through membranes of an SW30-2450 element before (pristine) and after modification of the membranes with 0.1, 0.5, 1 or 2 mM of n-decylamine (FIG. 9A) or n-dodecylamine (FIG. 9A) (testing conditions: 5 ppm boron, 15,000 ppm NaCl, pressure 40 bar).
  • FIGs. 10A and 10B present bar graphs showing salt passage of membranes of an SW30-2450 element before (pristine) and after modification of the membranes with 0.1, 0.5, 1 or 2 mM of n-decylamine (FIG. 10A) or n-dodecylamine (FIG. 10B) (testing conditions: 5 ppm boron, 15,000 ppm NaCl, pressure 40 bar).
  • FIG. 11 presents an ATR-FTIR (attenuated total reflectance Fourier transform infra-red) spectrum of a polyamide membrane (SW30) modified by sorption of decylamine or dodecylamine (modification conditions: pressure 10 bar, alkylamine concentration increased from 0.1 to 2 mM, thereafter the element was autopsied).
  • FIGs. 12A and 12B scanning electron microscopy images of a polyamide membrane (SW30) surface modified by sorption of decylamine (FIG. 12A) or dodecylamine (FIG. 12B) (modification conditions: pressure 10 bar, alkylamine concentration increased from 0.1 to 2 mM, thereafter the element was autopsied; scale bar in FIG. 12A is 200 nm).
  • FIG. 13 presents a graph showing the boron passage and water permeability (Lp) for pristine commercial seawater reverse osmosis (SWRO) membranes and SWRO membranes modified by sorption of amylamine (C5), octylamine (C8), decylamine (CIO) or dodecylamine (C12); solid symbols represent pristine membranes and open symbols represent modified membranes in conditions producing the most beneficial shift in performance (testing conditions: 5 ppm boron, 15,000 ppm NaCl, pressure 40 bar; except for SWRO data points (> ) which are for 5 ppm boron, 35,000 ppm NaCl, pressure 55 bar)
  • FIGs. 14A and 14B present graphs showing salt passage, boron passage and water permeability (Lp) of membranes of a brackish water reverse osmosis (BWRO) membrane (BW30) before (pristine) and after exposure to pH 11 for 24 hours resulting in hydrolytic degradation of the membrane, and after modification of the degraded membrane by 1 mM decylamine subsequently to hydrolysis, using carbodiimide-based coupling (FIG. 14A) or by sorption (FIG. 14B) (testing conditions: 5 ppm boron, 1,500 ppm NaCl, pressure 20 bar).
  • BWRO brackish water reverse osmosis
  • BWRO water reverse osmosis
  • the present invention in some embodiments thereof, relates to membranes for reverse osmosis, and more particularly, but not exclusively, to membranes for removing boron from water.
  • a water permeable composite membrane comprising a thin film layer on a porous substrate (as described in detail herein).
  • the thin film layer comprises a polymer and an amine-containing compound associated with the polymer (as described in detail herein), the amine-containing compound comprising at least one aliphatic hydrocarbon moiety attached to an amine group (as described in detail herein).
  • composite membrane encompasses any membrane comprising a thin film layer on a porous substrate (according to any of the respective embodiments described herein), and the term “composite” is not intended to be further limiting.
  • An amine-containing comprising at least one aliphatic hydrocarbon moiety attached to an amine group according to any of the respective embodiments described herein may be in accordance with any of the embodiments described in this section.
  • hydrocarbon describes an organic moiety that includes, as its basic skeleton, a chain of carbon atoms, substituted mainly by hydrogen atoms.
  • the hydrocarbon can be saturated or non-saturated, comprise aliphatic, alicyclic and/or aromatic moieties, and can optionally be substituted by one or more substituents (other than hydrogen).
  • the hydrocarbon moiety is optionally interrupted by one or more heteroatoms, including, without limitation, one or more oxygen, nitrogen and/or sulfur atoms.
  • aliphatic hydrocarbon moiety describes a hydrocarbon moiety as defined herein which comprises aliphatic and/or alicyclic moieties, and which is devoid of an aromatic moiety.
  • an aromatic hydrocarbon moiety may result in poor membrane performance.
  • the aliphatic hydrocarbon moiety described herein is not interrupted by any heteroatoms, although it is optionally substituted by one or more substituents comprising heteroatoms.
  • amine and “amino” each refer to either a - R'R” group or a -N + R'R"R"' group, wherein R', R" and R' " are each hydrogen or a saturated or unsaturated hydrocarbon moiety (as defined herein), the hydrocarbon moiety being substituted or non-substituted.
  • R', R" and R'" are hydrogen or alkyl comprising 1 to 4 carbon atoms.
  • R' and R" (and R'", if present) are hydrogen.
  • the carbon atom of an R', R" or R'" hydrocarbon moiety which is bound to the nitrogen atom of the amine is preferably not substituted by oxo, such that R', R" and R' " are not (for example) carbonyl, C-carboxy or amide, as these groups are defined herein, except where indicated otherwise.
  • the amine - containing compound associated with the polymer has the general formula:
  • Ri is an aliphatic hydrocarbon moiety according to any of the respective embodiments described herein;
  • R 2 and R 3 are each independently hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, or a heteroalicyclic, or, alternatively, one or both of R 2 and R 3 is independently a covalent bond linking the amine-containing compound to the polymer of the thin film or a group participating in a covalent bond linking the amine-containing compound to the polymer of the thin film.
  • the amine - containing compound (according to any of the respective embodiments described herein) is associated with the polymer via one or more non-covalent interactions.
  • non-covalent interactions include an ionic interaction and/or hydrogen bond between an amine group of the amine-containing compound (optionally in a positively charged form, e.g., a protonated form) and a group in the polymer (optionally a negatively charged group, e.g., a deprotonated carboxylic acid group), and a hydrophobic interaction, optionally between an aliphatic hydrocarbon moiety of the amine-containing compound and a suitably hydrophobic moiety (e.g., phenyl) of the polymer.
  • a positively charged form e.g., a protonated form
  • a group in the polymer optionally a negatively charged group, e.g., a deprotonated carboxylic acid group
  • hydrophobic interaction optionally between an aliphatic hydrocarbon moiety of the
  • the amine- containing compound has the general formula depicted herein, wherein R 2 and R 3 are each independently hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, or a heteroalicyclic. Such a compound may optionally be associated with the polymer via non-covalent interactions.
  • at least one of R 2 and R 3 is hydrogen.
  • R 2 and R 3 are each hydrogen.
  • the amine- containing compound (according to any of the respective embodiments described herein) is associated with the polymer via one or more (e.g., one or two) covalent bonds.
  • the covalent bond links an amine group of the amine- containing compound to the polymer.
  • the amine- containing compound has the general formula depicted herein, wherein at least one of R 2 and R 3 (optionally only R 3 ) is a covalent bond linking the amine-containing compound to the polymer.
  • R 3 is a covalent bond linking the amine-containing compound to the polymer
  • the amine-containing compound (in association with the polymer) is in a form of a moiety (e.g., univalent or divalent moiety) having the general formula:
  • Ri is an aliphatic hydrocarbon moiety according to any of the respective embodiments described herein;
  • R 2 is hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, or a heteroalicyclic (according to any of the respective embodiments described herein), or, alternatively, R 2 is a covalent bond linking the amine-containing compound to the polymer or a group participating in a covalent bond linking the amine-containing compound to the polymer (according to any of the respective embodiments described herein),
  • R 2 is hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, or a heteroalicyclic (according to any of the respective embodiments described herein), and the amine-containing compound is linked to the polymer by only one covalent bond (according to any of the respective embodiments described herein). In some such embodiments, R 2 is hydrogen.
  • R 2 and R 3 are each a covalent bond linking the amine- containing compound to the polymer (according to any of the respective embodiments described herein), and the amine-containing compound (in association with the polymer) is in a form of a moiety (e.g., divalent moiety) having the general formula:
  • Ri is an aliphatic hydrocarbon moiety according to any of the respective embodiments described herein, and the moiety is optionally linked to the polymer via one covalent bond represented herein by the variable R 2 and via another covalent bond represented herein by the variable R 3 (optionally groups in the polymer).
  • the covalent bond is an amide bond (e.g., R 2 and/or R 3 is a covalent amide bond).
  • such an amide bond is derived from a carboxylic group or acyl halide group in the polymer.
  • a group participating in a covalent bond linking the amine-containing compound to the polymer may optionally participate in one such covalent bond or in more than one such covalent bond (e.g., 2 or 3 covalent bonds).
  • a group participating in a covalent bond linking the amine-containing compound to the polymer is a hydrocarbon (as defined herein), which is optionally substituted or unsubstituted, and saturated or unsaturated.
  • the group is devoid of an aromatic moiety.
  • the hydrocarbon is a saturated hydrocarbon.
  • a group participating in a covalent bond linking the amine-containing compound to the polymer is from 1 to 10 atoms in length (i.e., the nitrogen atom of an amine group of the amine-containing compound is separated from the polymer by no more than 10 atoms).
  • the group is from 1 to 4 atoms in length.
  • the group is 1 or 2 atoms in length.
  • the group is a hydrocarbon having a length according to any of the aforementioned embodiments.
  • a group participating in a covalent bond linking the amine-containing compound to the polymer is a hydrocarbon substituted by oxo at a carbon atom attached directly to the nitrogen atom of an amine group of the amine-containing compound (e.g., as depicted in a general formula herein) such that the hydrocarbon is attached to the nitrogen atom via an amide bond.
  • a group participating in a covalent bond linking the amine-containing compound to the polymer comprises a functional group which forms a covalent bond with the polymer, and optionally more than one functional group which forms a covalent bond with the polymer.
  • the functional group(s) is attached to a hydrocarbon according to any of the respective embodiments described herein (e.g., as a substituent of a hydrocarbon).
  • the group participating in a covalent bond linking the amine-containing compound consists essentially of the aforementioned functional group(s) being attached to a (substituted or unsubstituted) hydrocarbon according to any of the respective embodiments described herein.
  • a nitrogen atom e.g., of an amine group, which optionally comprises a hydrocarbon described herein attached to the nitrogen atom
  • oxygen atom e.g., of an alkoxy group comprising the oxygen atom, optionally consisting of the oxygen atom and a hydrocarbon described herein
  • covalent bond e.g., an amide or ester bond
  • the covalent bond e.g., an amide or ester bond
  • at least a portion of (and optionally each of) the groups participating in a covalent bond linking the amine-containing compound to the polymer are derived from an additional compound linked to the polymer (e.g., the group represents at least a portion of a residue of the additional compound linked to the polymer).
  • Such an additional compound may optionally be reacted with an amine-containing compound to form an amine-containing compound comprising the aforementioned group, followed by formation of a covalent bond between the group and the polymer (e.g., the amine-containing compound comprising the aforementioned group is generated in a form of a molecule prior to being attached to the polymer), and/or the additional compound may optionally be reacted with the polymer to form a polymer attached to a residue of the additional compound, followed by formation of a covalent bond between the residue and the amine-containing compound (e.g., the amine-containing compound comprising the aforementioned group is generated in a form of a moiety attached to the polymer, and not in a form of a free molecule).
  • a LogP of the amine-containing compound (in a form of an isolated compound, as opposed, for example, to a moiety attached to the polymer) is at least 0.2. In some embodiments, the LogP of the amine-containing compound is at least 0.5. In some embodiments, the LogP is at least 1.0. In some embodiments, the LogP is at least 1.5. In some embodiments, the LogP is at least 2.0. In some embodiments, the LogP is at least 2.5. In some embodiments, the LogP is at least 3.0. In some embodiments, the LogP is at least 3.5. In some embodiments, the LogP is at least 4.0. In some embodiments, the LogP is at least 4.5. In some embodiments, the LogP is at least 5.0.
  • a LogP of the amine-containing compound (in a form of an isolated compound, as opposed, for example, to a moiety attached to the polymer) is no more than 7.0.
  • the LogP is in a range of from 0.2 to 7.0.
  • the LogP is in a range of from 0.5 to 7.0.
  • the LogP is in a range of from 1.0 to 7.0.
  • the LogP is in a range of from 1.5 to 7.0.
  • the LogP is in a range of from 2.0 to 7.0.
  • the LogP is in a range of from 2.5 to 7.0.
  • the LogP is in a range of from 3.0 to 7.0. In some embodiments, the LogP is in a range of from 3.5 to 7.0. In some embodiments, the LogP is in a range of from 4.0 to 7.0. In some embodiments, the LogP is in a range of from 4.5 to 7.0. In some embodiments, the LogP is in a range of from 5.0 to 7.0.
  • a LogP of the amine-containing compound (in a form of an isolated compound, as opposed, for example, to a moiety attached to the polymer) is no more than 6.0.
  • the LogP is in a range of from 0.2 to 6.0.
  • the LogP is in a range of from 0.5 to 6.0.
  • the LogP is in a range of from 1.0 to 6.0.
  • the LogP is in a range of from 1.5 to 6.0.
  • the LogP is in a range of from 2.0 to 6.0.
  • the LogP is in a range of from 2.5 to 6.0.
  • the LogP is in a range of from 3.0 to 6.0. In some embodiments, the LogP is in a range of from 3.5 to 6.0. In some embodiments, the LogP is in a range of from 4.0 to 6.0. In some embodiments, the LogP is in a range of from 4.5 to 6.0. In some embodiments, the LogP is in a range of from 5.0 to 6.0.
  • a LogP of the amine-containing compound (in a form of an isolated compound, as opposed, for example, to a moiety attached to the polymer) is no more than 5.5. In some such embodiments, the LogP is in a range of from 0.2 to 5.5. In some embodiments, the LogP is in a range of from 0.5 to 5.5. In some embodiments, the LogP is in a range of from 1.0 to 5.5. In some embodiments, the LogP is in a range of from 1.5 to 5.5. In some embodiments, the LogP is in a range of from 2.0 to 5.5. In some embodiments, the LogP is in a range of from 2.5 to 5.5.
  • the LogP is in a range of from 3.0 to 5.5. In some embodiments, the LogP is in a range of from 3.5 to 5.5. In some embodiments, the LogP is in a range of from 4.0 to 5.5. In some embodiments, the LogP is in a range of from 4.5 to 5.5.
  • a LogP of the amine-containing compound (in a form of an isolated compound, as opposed, for example, to a moiety attached to the polymer) is no more than 5.0.
  • the LogP is in a range of from 0.2 to 5.0.
  • the LogP is in a range of from 0.5 to 5.0.
  • the LogP is in a range of from 1.0 to 5.0.
  • the LogP is in a range of from 1.5 to 5.0.
  • the LogP is in a range of from 2.0 to 5.0.
  • the LogP is in a range of from 2.5 to 5.0.
  • the LogP is in a range of from 3.0 to 5.0.
  • the LogP is in a range of from 3.5 to 5.0.
  • the LogP is in a range of from 4.0 to 5.0.
  • logP refers to the base- 10 logarithm of an octanol-water partition coefficient of a compound (i.e., the logarithm of the ratio of the concentration of the compound in octanol to the concentration of the compound in water, when the compound is dissolved in an octanol-water system).
  • the compound is in a neutrally charged form in non-ionized water, and the LogP is determined at a pH at which the compound exists substantially as the neutrally charged form.
  • a positive value for a LogP indicates better solubility in octanol than in water, which may be considered as a sign of hydrophobicity.
  • Hydrophobicity (e.g., LogP) of the amine-containing compound may optionally be enhanced by a suitably hydrophobic aliphatic hydrocarbon moiety (e.g., according to any of the respective embodiments described herein).
  • logP refers to experimentally determined values.
  • a LogP of the amine-containing compound is calculated according to any suitable technique used in the art, for example, calculated based on the method described by Viswanadhan et al. [ Chem Inf Comput Sci 1989, 29:163-172] (e.g., LogP values available at the chemicalize(dot)org website) and/or as described in Bram et al. [Biochem Pharmacol (2007) 74:41-53], and the calculated LogP value is a value according to any of the embodiments described herein regarding LogP values.
  • the contents of Viswanadhan et al. [ Chem Inf Comput Sci 1989, 29: 163-172] and Bram et al. [Biochem Pharmacol (2007) 74:41-53] are incorporated by reference, especially contents therein regarding calculation of octanol-water partition and/or logP values.
  • a minimum projection area of the amine-containing compound (in a form of an isolated compound, as opposed, for example, to a moiety attached to the polymer) is no more than 31 A 2 . In some such embodiments, the minimum projection area of the amine-containing compound is no more than 30.5 A 2 . In some embodiments, the minimum projection area is no more than 30 A 2 . In some embodiments, the minimum projection area is no more than 29.5 A 2 . In some embodiments, the minimum projection area is no more than 29 A 2 . In some embodiments, the minimum projection area is no more than 28.5 A 2 . In some embodiments, the minimum projection area is no more than 28 A 2 . In some embodiments, the minimum projection area is no more than 27.5 A 2 . In some embodiments, the minimum projection area is no more than 27 A 2 .
  • a minimum projection area of the amine-containing compound (in a form of an isolated compound, as opposed, for example, to a moiety attached to the polymer) is at least 18 A 2 .
  • the minimum projection area of the amine-containing compound is in a range of from 18 to 31 A 2 .
  • the minimum projection area is in a range of from 18 to 30.5 A 2 .
  • the minimum projection area is in a range of from 18 to 30 A 2 .
  • the minimum projection area is in a range of from 18 to 29.5 A 2 .
  • the minimum projection area is in a range of from 18 to 29 A 2 .
  • the minimum projection area is in a range of from 18 to 28.5 A 2 . In some embodiments, the minimum projection area is in a range of from 18 to 28 A 2 . In some embodiments, the minimum projection area is in a range of from 18 to 27.5 A 2 . In some embodiments, the minimum projection area is in a range of from 18 to 27 A 2 .
  • a minimum projection area of the amine-containing compound (in a form of an isolated compound, as opposed, for example, to a moiety attached to the polymer) is at least 19 A 2 .
  • the minimum projection area of the amine-containing compound is in a range of from 19 to 31 A 2 .
  • the minimum projection area is in a range of from 19 to 30.5 A 2 .
  • the minimum projection area is in a range of from 19 to 30 A 2 .
  • the minimum projection area is in a range of from 19 to 29.5 A 2 .
  • the minimum projection area is in a range of from 19 to 29 A 2 .
  • the minimum projection area is in a range of from 19 to 28.5 A 2 . In some embodiments, the minimum projection area is in a range of from 19 to 28 A 2 . In some embodiments, the minimum projection area is in a range of from 19 to 27.5 A 2 . In some embodiments, the minimum projection area is in a range of from 19 to 27 A 2 .
  • a minimum projection area of the amine-containing compound (in a form of an isolated compound, as opposed, for example, to a moiety attached to the polymer) is at least 20 A 2 .
  • the minimum projection area of the amine-containing compound is in a range of from 20 to 31 A 2 .
  • the minimum projection area is in a range of from 20 to 30.5 A 2 .
  • the minimum projection area is in a range of from 20 to 30 A 2 .
  • the minimum projection area is in a range of from 20 to 29.5 A 2 .
  • the minimum projection area is in a range of from 20 to 29 A 2 .
  • the minimum projection area is in a range of from 20 to 28.5 A 2 . In some embodiments, the minimum projection area is in a range of from 20 to 28 A 2 . In some embodiments, the minimum projection area is in a range of from 20 to 27.5 A 2 . In some embodiments, the minimum projection area is in a range of from 20 to 27 A 2 .
  • a minimum projection area of the amine-containing compound (in a form of an isolated compound, as opposed, for example, to a moiety attached to the polymer) is at least 21 A 2 .
  • the minimum projection area of the amine-containing compound is in a range of from 21 to 31 A 2 .
  • the minimum projection area is in a range of from 21 to 30.5 A 2 .
  • the minimum projection area is in a range of from 21 to 30 A 2 .
  • the minimum projection area is in a range of from 21 to 29.5 A 2 .
  • the minimum projection area is in a range of from 21 to 29 A 2 .
  • the minimum projection area is in a range of from 21 to 28.5 A 2 . In some embodiments, the minimum projection area is in a range of from 21 to 28 A 2 . In some embodiments, the minimum projection area is in a range of from 21 to 27.5 A 2 . In some embodiments, the minimum projection area is in a range of from 21 to 27 A 2 .
  • a minimum projection area of the amine-containing compound (in a form of an isolated compound, as opposed, for example, to a moiety attached to the polymer) is at least 22 A 2 .
  • the minimum projection area of the amine-containing compound is in a range of from 22 to 31 A 2 .
  • the minimum projection area is in a range of from 22 to 30.5 A 2 .
  • the minimum projection area is in a range of from 22 to 30 A 2 .
  • the minimum projection area is in a range of from 22 to 29.5 A 2 .
  • the minimum projection area is in a range of from 22 to 29 A 2 .
  • the minimum projection area is in a range of from 22 to 28.5 A 2 . In some embodiments, the minimum projection area is in a range of from 22 to 28 A 2 . In some embodiments, the minimum projection area is in a range of from 22 to 27.5 A 2 . In some embodiments, the minimum projection area is in a range of from 22 to 27 A 2 .
  • a minimum projection area of the amine-containing compound (in a form of an isolated compound, as opposed, for example, to a moiety attached to the polymer) is at least 23 A 2 .
  • the minimum projection area of the amine-containing compound is in a range of from 23 to 31 A 2 .
  • the minimum projection area is in a range of from 23 to 30.5 A 2 .
  • the minimum projection area is in a range of from 23 to 30 A 2 .
  • the minimum projection area is in a range of from 23 to 29.5 A 2 .
  • the minimum projection area is in a range of from 23 to 29 A 2 .
  • the minimum projection area is in a range of from 23 to 28.5 A 2 . In some embodiments, the minimum projection area is in a range of from 23 to 28 A 2 . In some embodiments, the minimum projection area is in a range of from 23 to 27.5 A 2 . In some embodiments, the minimum projection area is in a range of from 23 to 27 A 2 .
  • a minimum projection area of the amine-containing compound (in a form of an isolated compound, as opposed, for example, to a moiety attached to the polymer) is at least 24 A 2 .
  • the minimum projection area of the amine-containing compound is in a range of from 24 to 31 A 2 .
  • the minimum projection area is in a range of from 24 to 30.5 A 2 .
  • the minimum projection area is in a range of from 24 to 30 A 2 .
  • the minimum projection area is in a range of from 24 to 29.5 A 2 .
  • the minimum projection area is in a range of from 24 to 29 A 2 .
  • the minimum projection area is in a range of from 24 to 28.5 A 2 . In some embodiments, the minimum projection area is in a range of from 24 to 28 A 2 . In some embodiments, the minimum projection area is in a range of from 24 to 27.5 A 2 . In some embodiments, the minimum projection area is in a range of from 24 to 27 A 2 .
  • a minimum projection area of the amine-containing compound (in a form of an isolated compound, as opposed, for example, to a moiety attached to the polymer) is at least 25 A 2 .
  • the minimum projection area of the amine-containing compound is in a range of from 25 to 31 A 2 .
  • the minimum projection area is in a range of from 25 to 30.5 A 2 .
  • the minimum projection area is in a range of from 25 to 30 A 2 .
  • the minimum projection area is in a range of from 25 to 29.5 A 2 .
  • the minimum projection area is in a range of from 25 to 29 A 2 .
  • the minimum projection area is in a range of from 25 to 28.5 A 2 . In some embodiments, the minimum projection area is in a range of from 25 to 28 A 2 . In some embodiments, the minimum projection area is in a range of from 25 to 27.5 A 2 . In some embodiments, the minimum projection area is in a range of from 25 to 27 A 2 .
  • a minimum projection area of the amine-containing compound (in a form of an isolated compound, as opposed, for example, to a moiety attached to the polymer) is at least 22 A 2 .
  • the minimum projection area of the amine-containing compound is in a range of from 26 to 31 A 2 .
  • the minimum projection area is in a range of from 26 to 30.5 A 2 .
  • the minimum projection area is in a range of from 26 to 30 A 2 .
  • the minimum projection area is in a range of from 26 to 29.5 A 2 .
  • the minimum projection area is in a range of from 26 to 29 A 2 .
  • the minimum projection area is in a range of from 26 to 28.5 A 2 . In some embodiments, the minimum projection area is in a range of from 26 to 28 A 2 . In some embodiments, the minimum projection area is in a range of from 26 to 27.5 A 2 . In some embodiments, the minimum projection area is in a range of from 26 to 27 A 2 .
  • MMA refers to the two-dimensional area of a molecule's three-dimensional van der Waals volume (wherein atoms are represented as spheres whose radius is the van der Waals radius) projected on a plane, wherein the molecule is oriented in such a way that the projected area has the minimal possible value (as compared with other possible orientations of the molecule).
  • MPA values may optionally be obtained using any appropriate software, e.g., such as available at the chemicalize(dot)org website.
  • An aliphatic hydrocarbon moiety (as defined herein) according to any of the respective embodiments described herein (including, without limitation, an Ri moiety described herein) may be in accordance with any of the embodiments described in this section.
  • the aliphatic hydrocarbon moiety may optionally have any size, and be saturated or unsaturated, and substituted or unsubstituted.
  • the aliphatic hydrocarbon moiety (according to any of the respective embodiments described herein) contains at least 3 carbon atoms. In some embodiments, the aliphatic hydrocarbon moiety contains at least 4 carbon atoms. In some embodiments, the aliphatic hydrocarbon moiety contains at least 5 carbon atoms. In some embodiments, the aliphatic hydrocarbon moiety contains at least 6 carbon atoms. In some embodiments, the aliphatic hydrocarbon moiety contains at least 7 carbon atoms. In some embodiments, the aliphatic hydrocarbon moiety contains at least 8 carbon atoms. In some embodiments, the aliphatic hydrocarbon moiety contains at least 9 carbon atoms.
  • the aliphatic hydrocarbon moiety contains at least 10 carbon atoms. In some embodiments, the aliphatic hydrocarbon moiety contains at least 11 carbon atoms. In some embodiments, the aliphatic hydrocarbon moiety contains at least 12 carbon atoms. In some embodiments, the aliphatic hydrocarbon moiety contains at least 13 carbon atoms. In some embodiments, the aliphatic hydrocarbon moiety contains at least 14 carbon atoms. In some embodiments, the aliphatic hydrocarbon moiety contains at least 15 carbon atoms.
  • the aliphatic hydrocarbon moiety is of from 1 to 30 carbon atoms in length. In some embodiments of any of the embodiments described herein, the aliphatic hydrocarbon moiety (according to any of the respective embodiments described herein) is at least 3 carbon atoms in length. In some embodiments, the aliphatic hydrocarbon moiety is at least 4 carbon atoms in length. In some embodiments, the aliphatic hydrocarbon moiety is at least 5 carbon atoms in length. In some embodiments, the aliphatic hydrocarbon moiety is at least 6 carbon atoms in length. In some embodiments, the aliphatic hydrocarbon moiety is at least 7 carbon atoms in length.
  • the aliphatic hydrocarbon moiety is at least 8 carbon atoms in length. In some embodiments, the aliphatic hydrocarbon moiety is at least 9 carbon atoms in length. In some embodiments, the aliphatic hydrocarbon moiety is at least 10 carbon atoms in length. In some embodiments, the aliphatic hydrocarbon moiety is at least 11 carbon atoms in length. In some embodiments, the aliphatic hydrocarbon moiety is at least 12 carbon atoms in length. In some embodiments, the aliphatic hydrocarbon moiety is at least 13 carbon atoms in length.
  • the aliphatic hydrocarbon moiety is at least 14 carbon atoms in length. In some embodiments, the aliphatic hydrocarbon moiety is at least 15 carbon atoms in length.
  • a "length" of an aliphatic hydrocarbon moiety refers to the number of carbon atoms in a linear chain, wherein the carbon atom at one terminus of the linear chain is closest (among all the atoms in the linear chain) to the amine group according to any of the respective embodiments described herein (and optionally attached to a nitrogen atom of the amine group), and the other atoms in the linear chain are progressively farther from the amine group, such that the other terminus of the linear chain is represented by the carbon atom farthest from the amine group.
  • linear chain with the greatest length is regarded as the length of the aliphatic hydrocarbon moiety.
  • the shortest of the two or more linear chains represents the distance of said carbon atom from the amine group, and is to be regarded as the length of the aliphatic hydrocarbon moiety (unless there exists a linear chain terminating at a different carbon atom which has a greater length).
  • the aliphatic hydrocarbon moiety (according to any of the respective embodiments described herein) contains at least 5 carbon atoms. In some such embodiments, the aliphatic hydrocarbon moiety contains at least 6 carbon atoms. In some such embodiments, the aliphatic hydrocarbon moiety contains at least 7 carbon atoms. In some such embodiments, the aliphatic hydrocarbon moiety contains at least 8 carbon atoms. In some such embodiments, the aliphatic hydrocarbon moiety contains at least 9 carbon atoms. In some such embodiments, the aliphatic hydrocarbon moiety contains at least 10 carbon atoms.
  • the aliphatic hydrocarbon moiety contains at least 11 carbon atoms. In some such embodiments, the aliphatic hydrocarbon moiety contains at least 12 carbon atoms. In some such embodiments, the aliphatic hydrocarbon moiety contains at least 13 carbon atoms. In some such embodiments, the aliphatic hydrocarbon moiety contains at least 14 carbon atoms. In some such embodiments, the aliphatic hydrocarbon moiety contains at least 15 carbon atoms.
  • the aliphatic hydrocarbon moiety (according to any of the respective embodiments described herein) is at least 5 carbon atoms in length. In some such embodiments, the aliphatic hydrocarbon moiety is at least 6 carbon atoms in length. In some such embodiments, the aliphatic hydrocarbon moiety is at least 7 carbon atoms in length. In some such embodiments, the aliphatic hydrocarbon moiety is at least 8 carbon atoms in length. In some such embodiments, the aliphatic hydrocarbon moiety is at least 9 carbon atoms in length.
  • the aliphatic hydrocarbon moiety is at least 10 carbon atoms in length. In some such embodiments, the aliphatic hydrocarbon moiety is at least 11 carbon atoms in length. In some such embodiments, the aliphatic hydrocarbon moiety is at least 12 carbon atoms in length.
  • the aliphatic hydrocarbon moiety is at least 13 carbon atoms in length. In some such embodiments, the aliphatic hydrocarbon moiety is at least 14 carbon atoms in length. In some such embodiments, the aliphatic hydrocarbon moiety is at least 15 carbon atoms in length.
  • a larger size (e.g., in terms of length and/or number of carbon atoms) of an aliphatic hydrocarbon moiety in the amine-containing compound may correlate with the ability of the amine-containing compound to efficiently associate with the polymer via non-covalent interactions.
  • the aliphatic hydrocarbon moiety according to any of the respective embodiments described herein consists of a linear aliphatic hydrocarbon moiety which is unsubstituted or is substituted by one or more substituents which may be, for example, alkyl, alkenyl, alkynyl, cycloalkyl, heteroalicyclic, halo, hydroxy, alkoxy, thiohydroxy, thioalkoxy, sulfinyl, sulfonyl, cyano, nitro, azide, phosphonyl, phosphinyl, oxo, carbonyl, thiocarbonyl, urea, thiourea, O-carbamyl, N-carbamyl, O-thiocarbamyl, N-thiocarbamyl, C-amido, NT- amido, C-carboxy, O-carboxy, sulfonamido, and
  • linear aliphatic hydrocarbon moiety describes an aliphatic hydrocarbon moiety as defined herein which does not comprise an alicyclic moiety, except optionally as a substituent of the linear aliphatic hydrocarbon moiety.
  • any substitution of a linear aliphatic hydrocarbon moiety described herein is relatively limited, such that the substitution does not greatly alter the linear character of the moiety structure.
  • the aliphatic hydrocarbon moiety consists of a linear aliphatic hydrocarbon moiety which is unsubstituted or is substituted by one or more substituents, each substituent being no more than 3 atoms in length. That is, each atom in a substituent is separated from the linear backbone chain of the hydrocarbon moiety by no more than two atoms (e.g., being attached directly to the linear backbone chain, attached to an atom which is attached to the linear backbone chain, and/or attached to an atom which is attached to an atom attached to the linear backbone chain).
  • substituents include, without limitation, Ci-2-alkyl (e.g., methyl, ethyl), C 2 -alkenyl (e.g., vinyl), O-alkynyl (e.g., ethynyl), and cyclopropyl, each being optionally substituted or unsubstituted (e.g., at the 1- and/or 2-position), and halo.
  • Ci-2-alkyl e.g., methyl, ethyl
  • C 2 -alkenyl e.g., vinyl
  • O-alkynyl e.g., ethynyl
  • cyclopropyl each being optionally substituted or unsubstituted (e.g., at the 1- and/or 2-position), and halo.
  • the aliphatic hydrocarbon moiety consists of a linear aliphatic hydrocarbon moiety which is unsubstituted or is substituted by one or more substituents, each substituent being no more than 2 atoms in length. That is, each atom in a substituent is separated from the linear backbone chain of the hydrocarbon moiety by no more than one atom (e.g., being attached directly to the linear backbone chain and/or attached to an atom which is attached to the linear backbone chain). In some of the aforementioned embodiments, each substituent contains no more than one atom which is not a hydrogen atom.
  • substituents include, without limitation, substituents which are 2 atoms in length, such as methyl (optionally unsubstituted or substituted by oxo or 1-3 halo substituents), hydroxyl, thiohydroxy and -NH 2 ; and substituents containing only one atom, such as halo and oxo.
  • the aliphatic hydrocarbon moiety consists of a linear aliphatic hydrocarbon moiety which is unsubstituted or is substituted by no more than three substituents. In some embodiments, the linear aliphatic hydrocarbon moiety is substituted by no more than two substituents. In some embodiments, the linear aliphatic hydrocarbon moiety is substituted by no more than one substituent. In some of the aforementioned embodiments, the aliphatic hydrocarbon moiety consists of an unsubstituted linear aliphatic hydrocarbon moiety.
  • the aliphatic hydrocarbon moiety consists of a linear aliphatic hydrocarbon moiety which is unsubstituted or is substituted, wherein if substituted the linear aliphatic hydrocarbon moiety comprises no more than one substituent attached to each carbon atom in the linear aliphatic hydrocarbon moiety.
  • a composite membrane according to any of the embodiments described herein comprises a thin film on a porous substrate, the thin film layer comprising a polymer and an amine-containing compound associated with the polymer (e.g., according to any of the any of the embodiments described herein relating to an amine-containing compound).
  • the composite membrane is made from two or more constituent materials with significantly different physical and/or chemical properties (e.g., in accordance with a commonly used definition of a "composite material"), for example, wherein the thin film layer comprises at least one of such materials and the porous layer comprises at least one other such materials.
  • a "thin film” or “thin film layer” refers to a layer of a material, preferably a polymeric material (e.g., a material comprising the polymer in the thin film layer according to any of the respective embodiments described herein), which has an average thickness of no more than 5 ⁇ .
  • an average thickness of the thin film layer is no more than 2 ⁇ . In some embodiments of any of the embodiments described herein, an average thickness of the thin film layer is no more than 1 ⁇ . In some embodiments of any of the embodiments described herein, an average thickness of the thin film layer is no more than 500 nm (0.5 ⁇ ). In some embodiments, an average thickness of the thin film layer is no more than 300 nm. In some embodiments, an average thickness of the thin film layer is no more than 200 nm. In some embodiments, an average thickness of the thin film layer is no more than 150 nm. In some embodiments, an average thickness of the thin film layer is no more than 100 nm.
  • an average thickness of the thin film layer is at least 15 nm. In some embodiments, an average thickness of the thin film layer is in a range of from 15 nm to 1 ⁇ . In some embodiments, an average thickness of the thin film layer is in a range of from 15 nm to 500 nm. In some embodiments, an average thickness of the thin film layer is in a range of from 15 nm to 300 nm. In some embodiments, an average thickness of the thin film layer is in a range of from 15 nm to 100 nm. In some embodiments, an average thickness of the thin film layer is in a range of from 15 nm to 50 nm.
  • an average thickness of the thin film layer is at least 50 nm. In some embodiments, an average thickness of the thin film layer is in a range of from 50 nm to 1 ⁇ . In some embodiments, an average thickness of the thin film layer is in a range of from 50 nm to 500 nm. In some embodiments, an average thickness of the thin film layer is in a range of from 50 nm to 300 nm.
  • an average thickness of the thin film layer is at least 100 nm. In some embodiments, an average thickness of the thin film layer is in a range of from 100 nm to 1 ⁇ . In some embodiments, an average thickness of the thin film layer is in a range of from 100 nm to 500 nm. In some embodiments, an average thickness of the thin film layer is in a range of from 100 nm to 300 nm. In some embodiments, an average thickness of the thin film layer is in a range of from 150 nm to 200 nm.
  • a “porous substrate” refers to a substrate which is sufficiently porous (e.g., with respect to a size of pores therein) to allow an aqueous solution (e.g., an aqueous solution of NaCl and boric acid described herein) to pass through the substrate without filtration of solutes on the solution.
  • an aqueous solution e.g., an aqueous solution of NaCl and boric acid described herein
  • a water permeability of the porous substrate is greater than a water permeability of the thin film layer, such that the porous substrate does not reduce a water permeability of the composite membrane considerably beyond a degree to which the thin film layer limits water permeability.
  • the porous substrate comprises a (porous) layer of a polymer, optionally polyethersulfone and/or polysulfone, upon which the thin film layer is deposited.
  • a porous layer include, without limitation, polyimide, polyamide, polyetherimide, polyacrylonitrile, polymethyl methacrylate, polyolefins (e.g., polyethylene, polypropylene) and halogenated olefins (e.g., polyvinylidene fluoride).
  • an average thickness of the layer of a polymer is in a range of from 5 to 500 ⁇ . In some embodiments, the average thickness is in a range of from 10 to 250 ⁇ . In some embodiments, the average thickness is in a range of from 25 to 100 ⁇ . In some embodiments, the average thickness is about 50 ⁇ .
  • the porous substrate further comprises a (porous) support sheet underlying the layer of a polymer (e.g., the layer of a polymer is between the support sheet and the thin film layer).
  • the sheet is a fabric sheet, optionally a non-woven fabric.
  • the support sheet preferably enhances a mechanical strength of the composite membrane.
  • the polymer in the thin film layer may be any individual polymer (homopolymer or copolymer) or mixture of polymers known in the art which are suitable for forming the thin film layer, for example, a thin film layer suitable for reverse osmosis.
  • polymers suitable for inclusion in a composite membrane include, without limitation cellulose acetate and polyamides.
  • the thin film layer comprises a polyamide.
  • the repeating units may optionally be derived from monomers comprising at least one carboxylic group and at least one amine group (which are linked form amide linking groups between units) and/or from monomers comprising at least two carboxylic groups in combination with monomers comprising at least two amine groups.
  • repeating units in a polyamide include, without limitation, units derived from a monomer comprising two or more carboxylic acid or acyl halide groups (e.g., units of adipate, succinate, cyclohexane dicarboxylic acid, cyclobutane dicarboxylic acid, cyclohexane tricarboxylic acid, cyclobutane tricarboxylic acid, terephthalate, phthalate, isophthalate, naphthalene dicarboxylic acid, biphenyl dicarboxylic acid, azobenzene dicarboxylic acid and benzene-tricarboxylic acid, or their corresponding acyl halides, each being optionally substituted or unsubstituted), which may optionally be form a polyamide in combination with units derived from a monomer comprising two or more amine groups (e.g., phenylenediamine, diaminotoluene, diamin
  • the polyamide comprises an aromatic polyamide, wherein at least a portion of the repeating units comprising an aromatic group.
  • the repeating units include, for example, phenylenediamine (e.g., m-phenylenediamine, p- phenylenediamine), xylylenediamine, triaminobenzene (e.g., 1,3,5-triaminobenzene, 1,3,4-triaminobenzene), diaminobenzoic acid (e.g., 3, 5 -diaminobenzoic acid), diaminotoluene (e.g., 2,4-diaminotoluene), diaminoanisole (e.g., 2,4-diaminoanisole), and terephthalate, phthalate, isophthalate, benzene-tricarboxylic acid (e.g., 1,3,5- benzene-tricarboxylic acid), biphenyl dicarbox
  • composite membrane suitable for use in reverse osmosis
  • a boron passage rate of the composite membrane is less than 35 %. In some such embodiments, the boron passage rate of the composite membrane is less than 30 %. In some such embodiments, the boron passage rate of the composite membrane is less than 30 %. In some such embodiments, the boron passage rate of the composite membrane is less than 25 %. In some such embodiments, the boron passage rate of the composite membrane is less than 20 %. In some such embodiments, the boron passage rate of the composite membrane is less than 15 %. In some such embodiments, the boron passage rate of the composite membrane is less than 12 %.
  • the boron passage rate of the composite membrane is less than 10 %. In some such embodiments, the boron passage rate of the composite membrane is less than 8 %. In some such embodiments, the boron passage rate of the composite membrane is less than 6 %.
  • a water permeability of the composite membrane is at least 0.2 liters per square meter per bar per hour (l-m "2 -baf ⁇ hour "1 ). In some such embodiments, the water permeability of the composite membrane is at least 0.25 l-m "2 -baf ⁇ hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 0.3 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 0.35
  • the water permeability of the composite membrane is at least 0.4 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.45 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.5 l-m “ 2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.55 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.6 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.65 l-m "
  • the water permeability of the composite membrane is at least 0.75 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.8 l-m “ 2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.85 l-m "2 - bar "1 -hour “1 .
  • the water permeability of the composite membrane is at least 0.9 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 1.0 l-m “ 2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 1.25 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 1.5 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 2.0 l-m " 2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 3.0 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 4.0 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 5.0 l-m " 2 ⁇ bar "1 -hour "1 .
  • a "boron passage” or “boron passage rate” (these terms being used herein interchangeably) of a membrane refers to the concentration of boric acid (including both undissociated boric acid and borate ion) measured as total B (e.g., by inductively coupled plasma (ICP) analysis) in a permeate (i.e., after a passage of a boric acid-containing feed solution once through the membrane) divided by the concentration of boric acid (including undissociated boric acid and borate ion) measured as total B in the feed solution (i.e., prior to passage of the feed solution through the membrane), the ratio optionally being expressed as a percentage (by multiplying a ratio by 100 %).
  • ICP inductively coupled plasma
  • a "water permeability" of a membrane refers to an amount of an aqueous solution (e.g., as measured in liters) which passes through the membrane per unit time, divided by the product of the area of the membrane (optionally 11.3 cm 2 ) and the feed pressure (optionally 55 bar).
  • a boron passage rate and/or water permeability according to any one of the respective embodiments described herein is determined under the following conditions: aqueous solution of boric acid (5ppm) and NaCl (32,000 ppm) at pH 7, and at a feed pressure of 55 bar.
  • the boron passage rate and/or water permeability may optionally be determined using a 150 ml pressurized (e.g., nitrogen-pressurized) dead-end stirred cell having a membrane area of 11.3 cm 2 , as exemplified herein.
  • a boron passage rate of the composite membrane is less than 35 %, and a water permeability of the composite membrane is at least 0.2 liters per square meter per bar per hour (l-m " 2 -bar “1 -hour “1 ). In some such embodiments, the water permeability of the composite membrane is at least 0.25 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 0.3 l-m "2 - bar "1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.35 l-m " 2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 0.4 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 0.45 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.5 l-m " 2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.55 l-m "2 - bar "1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.6 l-m "2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 0.65 l-m " 2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.8 l-m " 2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.85 l-m "2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 0.9 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 1.0 l-m “ 2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 1.25 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 1.5 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 2.0 l-m " 2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 3.0 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 4.0 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 5.0 l-m " 2 - bar "1 -hour "1 .
  • a boron passage rate of the composite membrane is less than 30 %, and a water permeability of the composite membrane is at least 0.2 liters per square meter per bar per hour (l-m " 2 -bar “1 -hour “1 ). In some such embodiments, the water permeability of the composite membrane is at least 0.25 l-m "2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.3 l-m "2 - bar "1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.35 l-m " 2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 0.4 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 0.45 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.5 l-m " 2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.55 l-m "2 - bar "1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.6 l-m "2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 0.65 l-m " 2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.8 l-m " 2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.85 l-m "2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 0.9 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 1.0 l-m “ 2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 1.25 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 1.5 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 2.0 l-m " 2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 3.0 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 4.0 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 5.0 l-m " 2 - bar "1 -hour "1 .
  • a boron passage rate of the composite membrane is less than 25 %, and a water permeability of the composite membrane is at least 0.2 liters per square meter per bar per hour (l-m " 2 -bar “1 -hour “1 ). In some such embodiments, the water permeability of the composite membrane is at least 0.25 l-m "2 - bar “1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 0.3 l-m "2 - bar "1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.35 l-m " 2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 0.4 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 0.45 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.5 l-m " 2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.55 l-m "2 - bar "1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.6 l-m "2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 0.65 l-m " 2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.8 l-m " 2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.85 l-m "2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 0.9 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 1.0 l-m “ 2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 1.25 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 1.5 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 2.0 l-m " 2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 3.0 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 4.0 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 5.0 l-m " 2 - bar "1 -hour "1 .
  • a boron passage rate of the composite membrane is less than 20 %, and a water permeability of the composite membrane is at least 0.2 liters per square meter per bar per hour (l-m " 2 -bar “1 -hour “1 ). In some such embodiments, the water permeability of the composite membrane is at least 0.25 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 0.3 l-m "2 - bar "1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.35 l-m " 2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 0.4 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 0.45 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.5 l-m " 2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.55 l-m "2 - bar "1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.6 l-m "2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 0.65 l-m " 2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.8 l-m " 2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.85 l-m "2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 0.9 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 1.0 l-m “ 2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 1.25 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 1.5 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 2.0 l-m " 2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 3.0 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 4.0 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 5.0 l-m " 2 - bar "1 -hour "1 .
  • a boron passage rate of the composite membrane is less than 15 %, and a water permeability of the composite membrane is at least 0.2 liters per square meter per bar per hour (l-m " 2 -bar “1 -hour “1 ). In some such embodiments, the water permeability of the composite membrane is at least 0.25 l-m "2 - bar “1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 0.3 l-m "2 - bar "1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.35 l-m " 2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 0.4 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 0.45 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.5 l-m " 2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.55 l-m "2 - bar "1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.6 l-m "2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 0.65 l-m " 2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.8 l-m " 2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.85 l-m "2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 0.9 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 1.0 l-m “ 2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 1.25 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 1.5 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 2.0 l-m " 2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 3.0 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 4.0 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 5.0 l-m " 2 - bar "1 -hour "1 .
  • a boron passage rate of the composite membrane is less than 12 %, and a water permeability of the composite membrane is at least 0.2 liters per square meter per bar per hour (l-m " 2 -bar “1 -hour “1 ). In some such embodiments, the water permeability of the composite membrane is at least 0.25 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 0.3 l-m "2 - bar "1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.35 l-m " 2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 0.4 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 0.45 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.5 l-m " 2 ⁇ bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 0.55 l-m "2 - bar "1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.6 l-m "2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 0.65 l-m " 2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m "2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m "2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 0.8 l-m "2 - bar "1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.85 l-m “2 - bar "1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.9 l-m ⁇ bar ⁇ hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 1.0 l-m "2 - bar “1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 1.25 l-m ⁇ bar ⁇ hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 1.5 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 2.0
  • the water permeability of the composite membrane is at least 3.0 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 4.0 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 5.0 l-m "
  • a boron passage rate of the composite membrane is less than 10 %, and a water permeability of the composite membrane is at least 0.2 liters per square meter per bar per hour (l-m " 2 -bar “1 -hour “1 ). In some such embodiments, the water permeability of the composite membrane is at least 0.25 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 0.3 l-m "2 - bar "1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.35 l-m " 2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 0.4 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 0.45 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.5 l-m " 2 ⁇ bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 0.55 l-m "2 - bar "1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.6 l-m "2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 0.65 l-m " 2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m "2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m "2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 0.8 l-m "2 - bar "1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.85 l-m “2 - bar "1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.9 l-m ⁇ bar ⁇ hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 1.0 l-m "2 - bar “1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 1.25 l-m ⁇ bar ⁇ hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 1.5 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 2.0
  • the water permeability of the composite membrane is at least 3.0 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 4.0 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 5.0 l-m "
  • a boron passage rate of the composite membrane is less than 8 %, and a water permeability of the composite membrane is at least 0.2 liters per square meter per bar per hour (l-m " 2 -bar “1 -hour “1 ). In some such embodiments, the water permeability of the composite membrane is at least 0.25 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 0.3 l-m "2 - bar "1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.35 l-m " 2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 0.4 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 0.45 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.5 l-m " 2 ⁇ bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 0.55 l-m "2 - bar "1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.6 l-m "2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 0.65 l-m " 2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m "2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m "2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 0.8 l-m "2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.85 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.9 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 1.0 l-m "2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 1.25 l-m ⁇ bar ⁇ hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 1.5 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 2.0
  • the water permeability of the composite membrane is at least 3.0 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 4.0 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 5.0 l-m "
  • a boron passage rate of the composite membrane is less than 6 %, and a water permeability of the composite membrane is at least 0.2 liters per square meter per bar per hour (l-m " 2 -bar “1 -hour “1 ). In some such embodiments, the water permeability of the composite membrane is at least 0.25 l-m "2 - bar “1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 0.3 l-m "2 - bar "1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.35 l-m " 2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 0.4 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 0.45 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.5 l-m " 2 ⁇ bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 0.55 l-m "2 - bar "1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.6 l-m "2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 0.65 l-m " 2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m "2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m "2 - bar "1 -hour "1 .
  • the water permeability of the composite membrane is at least 0.8 l-m "2 - bar "1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.85 l-m “2 - bar "1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 0.9 l-m ⁇ bar ⁇ hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 1.0 l-m "2 - bar “1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 1.25 l-m ⁇ bar ⁇ hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 1.5 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 2.0
  • the water permeability of the composite membrane is at least 3.0 l-m "2 - bar "1 -hour "1 . In some such embodiments, the water permeability of the composite membrane is at least 4.0 l-m “2 - bar “1 -hour “1 . In some such embodiments, the water permeability of the composite membrane is at least 5.0 l-m "
  • a ratio of a boron passage rate of the composite membrane to water permeability of the composite membrane is less than 30 % boron passage rate per 1.0 liter per square meter per bar per hour water permeability (30 % per l-m ⁇ bar ⁇ hour "1 ). In some such embodiments, the ratio is less than 25 % boron passage rate per 1.0 liter per square meter per bar per hour water permeability (25 % per l-m ⁇ bar ⁇ hour "1 ).
  • the ratio is less than 20 % boron passage rate per 1.0 liter per square meter per bar per hour water permeability (20 % per l-m ⁇ bar ⁇ hour "1 ). In some such embodiments, the ratio is less than 15 % boron passage rate per 1.0 liter per square meter per bar per hour water permeability (15 % per l-m ⁇ bar ⁇ hour "1 ). In some such embodiments, the ratio is less than 10 % boron passage rate per 1.0 liter per square meter per bar per hour water permeability (10 % per l-m ⁇ bar ⁇ hour 1 ).
  • a boron passage rate and/or water permeability of a composite membrane according to embodiments of the invention may be affected by the properties of components of the composite membrane other than an amine-containing compound (according to any of the respective embodiments described herein), such as the polymer described herein, an effect of the amine-containing compound (according to any of the respective embodiments described herein) on embodiments of the invention may optionally be characterized by comparing a boron passage rate and/or water permeability of a composite membrane according to embodiments of the invention with the boron passage rate and/or water permeability a corresponding composite membrane without the amine-containing compound covalently and/or non-covalently bound to the polymer.
  • a boron passage rate of the composite membrane is less than 80 % of a boron passage rate of a corresponding composite membrane without the amine-containing compound covalently and/or non-covalently bound to the polymer (e.g., the boron passage rate is reduced by over 20 % due to the presence of the amine-containing compound). In some such embodiments, a boron passage rate of the composite membrane is less than 70 % of a boron passage rate of the aforementioned corresponding composite membrane without the amine-containing compound.
  • a boron passage rate of the composite membrane is less than 60 % of a boron passage rate of the corresponding composite membrane without the amine-containing compound. In some such embodiments, a boron passage rate of the composite membrane is less than 50 % of a boron passage rate of the corresponding composite membrane without the amine - containing compound. In some such embodiments, a boron passage rate of the composite membrane is less than 40 % of a boron passage rate of the corresponding composite membrane without the amine-containing compound. In some such embodiments, a boron passage rate of the composite membrane is less than 30 % of a boron passage rate of the corresponding composite membrane without the amine - containing compound.
  • a water permeability of the composite membrane is at least 20 % of a water permeability of a corresponding composite membrane without the amine-containing compound covalently and/or non-covalently bound to the polymer (e.g., the water permeability is reduced by no more than 80 % due to the presence of the amine-containing compound).
  • a water permeability of the composite membrane is at least 30 % of a water permeability of the aforementioned corresponding composite membrane.
  • a water permeability of the composite membrane is at least 40 % of a water permeability of the corresponding composite membrane.
  • a water permeability of the composite membrane is at least 50 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 60 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 70 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 80 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 90 % of a water permeability of the corresponding composite membrane.
  • a water permeability of the composite membrane is at least 100 % of a water permeability of the corresponding composite membrane (e.g., the water permeability is not reduced at all, and is optionally increased, due to the presence of the amine-containing compound).
  • a boron passage rate of the composite membrane is less than 80 % of a boron passage rate of a corresponding composite membrane without the amine-containing compound covalently and/or non-covalently bound to the polymer, and a water permeability of the composite membrane is at least 20 % of a water permeability of the aforementioned corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 30 % of a water permeability of the aforementioned corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 40 % of a water permeability of the corresponding composite membrane.
  • a water permeability of the composite membrane is at least 50 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 60 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 70 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 80 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 90 % of a water permeability of the corresponding composite membrane.
  • a water permeability of the composite membrane is at least 100 % of a water permeability of the corresponding composite membrane (e.g., the water permeability is not reduced at all, and is optionally increased, due to the presence of the amine-containing compound).
  • a boron passage rate of the composite membrane is less than 70 % of a boron passage rate of a corresponding composite membrane without the amine-containing compound covalently and/or non-covalently bound to the polymer, and a water permeability of the composite membrane is at least 20 % of a water permeability of the aforementioned corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 30 % of a water permeability of the aforementioned corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 40 % of a water permeability of the corresponding composite membrane.
  • a water permeability of the composite membrane is at least 50 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 60 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 70 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 80 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 90 % of a water permeability of the corresponding composite membrane.
  • a water permeability of the composite membrane is at least 100 % of a water permeability of the corresponding composite membrane (e.g., the water permeability is not reduced at all, and is optionally increased, due to the presence of the amine-containing compound).
  • a boron passage rate of the composite membrane is less than 60 % of a boron passage rate of a corresponding composite membrane without the amine-containing compound covalently and/or non-covalently bound to the polymer, and a water permeability of the composite membrane is at least 20 % of a water permeability of the aforementioned corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 30 % of a water permeability of the aforementioned corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 40 % of a water permeability of the corresponding composite membrane.
  • a water permeability of the composite membrane is at least 50 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 60 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 70 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 80 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 90 % of a water permeability of the corresponding composite membrane.
  • a water permeability of the composite membrane is at least 100 % of a water permeability of the corresponding composite membrane (e.g., the water permeability is not reduced at all, and is optionally increased, due to the presence of the amine-containing compound).
  • a boron passage rate of the composite membrane is less than 50 % of a boron passage rate of a corresponding composite membrane without the amine-containing compound covalently and/or non-covalently bound to the polymer, and a water permeability of the composite membrane is at least 20 % of a water permeability of the aforementioned corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 30 % of a water permeability of the aforementioned corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 40 % of a water permeability of the corresponding composite membrane.
  • a water permeability of the composite membrane is at least 50 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 60 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 70 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 80 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 90 % of a water permeability of the corresponding composite membrane.
  • a water permeability of the composite membrane is at least 100 % of a water permeability of the corresponding composite membrane (e.g., the water permeability is not reduced at all, and is optionally increased, due to the presence of the amine-containing compound).
  • a boron passage rate of the composite membrane is less than 40 % of a boron passage rate of a corresponding composite membrane without the amine-containing compound covalently and/or non-covalently bound to the polymer, and a water permeability of the composite membrane is at least 20 % of a water permeability of the aforementioned corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 30 % of a water permeability of the aforementioned corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 40 % of a water permeability of the corresponding composite membrane.
  • a water permeability of the composite membrane is at least 50 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 60 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 70 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 80 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 90 % of a water permeability of the corresponding composite membrane.
  • a water permeability of the composite membrane is at least 100 % of a water permeability of the corresponding composite membrane (e.g., the water permeability is not reduced at all, and is optionally increased, due to the presence of the amine-containing compound).
  • a boron passage rate of the composite membrane is less than 30 % of a boron passage rate of a corresponding composite membrane without the amine-containing compound covalently and/or non-covalently bound to the polymer, and a water permeability of the composite membrane is at least 20 % of a water permeability of the aforementioned corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 30 % of a water permeability of the aforementioned corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 40 % of a water permeability of the corresponding composite membrane.
  • a water permeability of the composite membrane is at least 50 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 60 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 70 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 80 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 90 % of a water permeability of the corresponding composite membrane.
  • a water permeability of the composite membrane is at least 100 % of a water permeability of the corresponding composite membrane (e.g., the water permeability is not reduced at all, and is optionally increased, due to the presence of the amine-containing compound).
  • a ratio of a boron passage rate to water permeability of the composite membrane is less than 90 % of a ratio of a boron passage rate to water permeability of a corresponding composite membrane without the amine-containing compound covalently and/or non-covalently bound to the polymer.
  • the ratio of boron passage rate to water permeability of the composite membrane is less than 80 % of a ratio of boron passage rate to water permeability of the aforementioned corresponding composite membrane.
  • the ratio of boron passage rate to water permeability of the composite membrane is less than 70 % of a ratio of boron passage rate to water permeability of the aforementioned corresponding composite membrane. In some embodiments, the ratio of boron passage rate to water permeability of the composite membrane is less than 60 % of a ratio of boron passage rate to water permeability of the aforementioned corresponding composite membrane. In some embodiments, the ratio of boron passage rate to water permeability of the composite membrane is less than 50 % of a ratio of boron passage rate to water permeability of the aforementioned corresponding composite membrane.
  • the ratio of boron passage rate to water permeability of the composite membrane is less than 40 % of a ratio of boron passage rate to water permeability of the aforementioned corresponding composite membrane. In some embodiments, the ratio of boron passage rate to water permeability of the composite membrane is less than 30 % of a ratio of boron passage rate to water permeability of the aforementioned corresponding composite membrane.
  • the ratio of boron passage rate to water permeability of the composite membrane is less than 20 % of a ratio of boron passage rate to water permeability of the aforementioned corresponding composite membrane.
  • a corresponding composite membrane is subjected to the same conditions as the composite membrane (e.g., according to any of the respective embodiments described herein) being compared thereto.
  • the corresponding composite membrane is one which has been used and/or degraded under corresponding conditions.
  • a process for preparing the water permeable composite membrane according to any of the respective embodiments described herein comprising contacting a thin film layer comprising a polymer described herein (according to any of the embodiments described herein relating to a thin film layer and/or polymer) with an amine-containing compound described herein (according to any of the embodiments described herein relating to an amine-containing compound).
  • the thin film layer comprising a polymer may optionally be prepared according to any technique known in the art for preparing a thin film layer suitable for a water permeable composite membrane (e.g., a composite membrane suitable for reverse osmosis), and may optionally be obtained from a commercial source.
  • a water permeable composite membrane e.g., a composite membrane suitable for reverse osmosis
  • the thin film layer When contacting a thin film layer with an amine-containing compound, the thin film layer is optionally in a form of a component of a composite membrane comprising the thin film layer on a porous substrate, for example, a composite membrane according to any of the respective embodiments described herein, but without the amine-containing compound therein.
  • the process further comprises contacting the thin film layer with an activator of a group in the polymer (e.g., prior to and/or concomitantly with contacting the thin film layer comprising a polymer with an amine-containing compound), the activator being capable of forming a covalent bond between the polymer and the amine-containing compound, for example, by forming a covalent bond between a group in the polymer and an amine group in the amine-containing compound. Any suitable activator known in the art may be used.
  • the polymer comprises free carboxylic acid groups, e.g., prior to contacting the thin film layer comprising a polymer with an amine-containing compound (according to any of the respective embodiments described herein).
  • the process further comprises contacting the thin film layer with an activator of carboxylic acid groups (e.g., prior to and/or concomitantly with contacting the thin film layer comprising a polymer with an amine-containing compound), the activator being capable of forming a covalent bond between carboxylic acid groups and the amine-containing compound, for example, by forming an amide bond between carboxylic acid groups and amine groups.
  • suitable amide-bond-forming activators include, without limitation, coupling agents such as carbodiimide agents (e.g., any carbodiimide agent used in the art), which may be used with or without an additional activator such as N-hydroxysuccinimide (which forms an activated ester).
  • the polymer comprises both free carboxylic groups and amide groups within the polymer (e.g., the polymer comprises a polyamide), and a ratio of free carboxylic acid groups to amide groups in the polymer prior to contacting the thin film layer with an activator of carboxylic acid groups (if the embodiment includes use of an activator) is in a range of from 1:50 to 1: 1 (free carboxylic acid groups:amide groups). In some embodiments, the ratio is in a range of from 1:25 to 1:2. In some embodiments, the ratio is in a range of from 1: 15 to 1:4.
  • a ratio of free carboxylic acid groups to amide groups in the polymer prior to contacting the thin film layer with an activator of carboxylic acid groups is in a range of from 1:50 to 1:2 (free carboxylic acid groups:amide groups). In some embodiments, the ratio is in a range of from 1:50 to 1:4. In some embodiments, the ratio is in a range of from 1:50 to 1:8. In some embodiments, the ratio is in a range of from 1:50 to 1: 15. In some embodiments, the ratio is in a range of from 1:50 to 1:25.
  • a ratio of free carboxylic acid groups to amide groups in the polymer prior to contacting the thin film layer with an activator of carboxylic acid groups is in a range of from 1:25 to 1: 1 (free carboxylic acid groups:amide groups). In some embodiments, the ratio is in a range of from 1: 15 to 1: 1. In some embodiments, the ratio is in a range of from 1:8 to 1: 1. In some embodiments, the ratio is in a range of from 1:4 to 1: 1. In some embodiments, the ratio is in a range of from 1:2 to 1: 1.
  • contacting the thin film layer with the amine-containing compound described herein is effected by contacting the thin film layer with a solution of the amine-containing compound.
  • the solution is an aqueous solution.
  • a concentration of the amine-containing compound in the solution contacted with the thin film layer is selected such that a desirable boron passage rate (e.g., a boron passage rate according to any of the respective embodiments described herein) is obtained, for example, by selecting a concentration of amine-containing compound which is sufficiently high so as to reduce the boron passage rate of a given thin film layer to a desired range (e.g., to below 20 %, below 15 %, below 12 %, below 10 %, below 8 %, or even below 6 %).
  • a desirable boron passage rate e.g., a boron passage rate according to any of the respective embodiments described herein
  • a concentration of the amine-containing compound in the solution contacted with the thin film layer is selected such that a desirable water permeability (e.g., a water permeability according to any of the respective embodiments described herein) is obtained, for example, by selecting a concentration of amine-containing compound which is sufficiently low so as to avoid reducing the water permeability to below a desired minimal level (e.g., 0.2 l-m ⁇ bar ⁇ hour 1 ).
  • a concentration of the amine-containing compound (e.g., a compound comprising a relatively large aliphatic hydrocarbon moiety described herein) in the solution contacted with the thin film layer is limited by the solubility of the amine-containing compound (e.g., solubility in aqueous solution), such that the concentration of amine-containing compound is about that of a saturated solution of the amine-containing compound or lower.
  • the thin film layer contacted with the solution of amine-containing compound is a degraded thin film layer which has been used to treat water.
  • the process for preparing the water permeable composite membrane from the degraded thin film layer is for at least partially restoring the degraded thin film layer.
  • the term "degraded” refers to a decrease in a boron rejection and/or salt rejection (i.e., an increase in boron passage and/or salt passage) associated with a thin film layer of a composite membrane (e.g., relative to the same thin film layer prior to use thereof to treat water).
  • the "restoring" a degraded thin film layer refers to reversing (at least partially) a change in at least one property associated with the degraded thin film layer (e.g., reversing a decrease in boron rejection and/or a decrease in salt rejection).
  • the value for the relevant parameter(s) of the thin film layer e.g., boron rejection and/or salt rejection
  • Restoring may optionally be partial, such that upon restoring the value for the relevant parameter(s) of the thin film layer is between the initial value and the value for the degraded thin film layer.
  • restoring may be complete, such that that the value for the relevant parameter(s) of the thin film layer upon restoring is equal to the initial value, or the initial value is between the value upon restoring and the value for the degraded thin film layer.
  • the degraded thin film layer is one which has underwent hydrolysis of a portion of the amide bonds in the polyamide therein (e.g., during use of the thin film layer to treat water).
  • the degraded thin film layer is characterized by an increase in boron passage associated with the thin film layer (e.g., relative to the same thin film layer prior to use thereof to treat water).
  • the boron passage of the degraded thin film layer is at least 110 % of the boron passage of the thin film layer prior to use thereof in treating water.
  • the boron passage of the degraded thin film layer is at least 120 % of the boron passage of the thin film layer prior to use thereof in treating water.
  • the boron passage of the degraded thin film layer is at least 130 % of the boron passage of the thin film layer prior to use thereof in treating water.
  • the boron passage of the degraded thin film layer is at least 140 % of the boron passage of the thin film layer prior to use thereof in treating water. In some embodiments, the boron passage of the degraded thin film layer is at least 150 % of the boron passage of the thin film layer prior to use thereof in treating water. In some embodiments, the boron passage of the degraded thin film layer is at least 175 % of the boron passage of the thin film layer prior to use thereof in treating water. In some embodiments, the boron passage of the degraded thin film layer is at least 200 % (two-fold) of the boron passage of the thin film layer prior to use thereof in treating water. In some embodiments, the boron passage of the degraded thin film layer is at least 300 % (3-fold) of the boron passage of the thin film layer prior to use thereof in treating water.
  • the degraded thin film layer is one which has been used to treat water at an alkaline pH, for example, in order to facilitate removal of boric acid (e.g., by ionizing boric acid).
  • the degraded thin film layer is one which has been used to treat water at a pH of at least 8.
  • the degraded thin film layer is one which has been used to treat water at a pH of at least 8.5.
  • the degraded thin film layer is one which has been used to treat water at a pH of at least 9.
  • the degraded thin film layer is one which has been used to treat water at a pH of at least 9.5.
  • the degraded thin film layer is used to treat water which has already passed through one or more other composite membrane, for example, the degraded thin film layer is comprised by a second pass, third pass, and/or fourth pass composite membrane.
  • the degraded thin film layer is used to treat partially desalinated water (e.g., obtained from seawater) obtained by the aforementioned one or more other composite membrane.
  • the degraded thin film layer is a composite membrane adapted for reverse osmosis of brackish water (e.g., a commercial brackish water reverse osmosis membrane), which has been subsequently degraded.
  • a boron rejection rate of the composite membrane is in a range of from 30 % to 80 %.
  • the thin film layer is contacted with the solution of amine-containing compound in situ, that is, wherein a composite membrane comprising the thin film layer is in functional communication with an apparatus configured for passing water through the composite membrane (e.g., a commercial water treatment apparatus).
  • the thin film layer is a degraded thin film layer (e.g., due to use of the composite membrane with the apparatus), which is optionally restored (according to any of the respective embodiments described herein) in situ (e.g., without necessitating removal of the composite membrane from the apparatus).
  • preparation is effected by non-covalent binding (e.g., sorption) of the amine-containing compound to the membrane, according to any of the respective embodiments described herein.
  • a method of treating water comprising passing water with solutes through a water permeable composite membrane according to any of the respective embodiments described herein, thereby treating the water.
  • the solutes include, without limitation, at least one (dissolved) salt and/or boric acid.
  • the solutes include boric acid.
  • salts include, without limitation salts comprising an alkali metal cation (e.g., Na + , K + ), an alkali earth metal cation (e.g., Mg 2+ , Ca 2+ ) and/or a halide anion (e.g., CI " ).
  • Passing the water with solutes through the water permeable composite membrane according to any of the respective embodiments described herein may optionally be effected by applying a suitable pressure difference between the water on each of the two sides of the membrane (e.g., so as to perform reverse osmosis, in which the applied pressure difference overcomes the osmotic pressure associated with the combination of the membrane and water with solutes), including by applying a greater than atmospheric pressure on one side of the membrane (e.g., using gravity and/or any suitable pumping technique) and/or applying a lower than atmospheric pressure on the other side of the membrane (e.g., using any suitable suction technique).
  • a suitable pressure difference between the water on each of the two sides of the membrane e.g., so as to perform reverse osmosis, in which the applied pressure difference overcomes the osmotic pressure associated with the combination of the membrane and water with solutes
  • a suitable pressure difference between the water on each of the two sides of the membrane
  • a suitable pressure difference between the water
  • treating the water comprises reducing a concentration of boron in the water to less than 1.0 ppm. In some embodiments, treating the water comprises reducing a concentration of boron in the water to less than 0.8 ppm. In some embodiments, treating the water comprises reducing a concentration of boron in the water to less than 0.6 ppm. In some embodiments, treating the water comprises reducing a concentration of boron in the water to less than 0.5 ppm. In some embodiments, treating the water comprises reducing a concentration of boron in the water to less than 0.4 ppm.
  • treating the water comprises reducing a concentration of boron in the water to less than 0.3 ppm. In some embodiments, treating the water comprises reducing a concentration of boron in the water to less than 0.2 ppm. In some embodiments, treating the water comprises reducing a concentration of boron in the water to less than 0.1 ppm.
  • a concentration of a solute in ppm (parts per million) units refers to the weight of solute relative to the weight of sample (e.g., a water sample).
  • a concentration of boron in ppm (parts per million) units refers to the weight of boron atoms relative to the weight of sample (e.g., a water sample with one or more dissolved boron-containing compounds), regardless of what boron- containing compound(s) is present in the sample.
  • passing the water through the water permeable composite membrane is effected no more than three times.
  • passing the water through the water permeable composite membrane is effected no more than twice.
  • passing the water through the water permeable composite membrane is effected no more than once.
  • a suitable number of times in which water is passed through a water permeable composite membrane may be determined by the skilled practitioner based on economic considerations, a desired final concentration of solutes (e.g., boron), and the concentrations and species of solutes in the water to be treated.
  • solutes e.g., boron
  • the water passed through the water permeable composite membrane has an alkaline pH, for example, in order to facilitate removal of boric acid (e.g., by ionizing boric acid).
  • the water has a pH of at least 8.
  • the water has a pH of at least 8.5.
  • the water has a pH of at least 9.
  • the water has a pH of at least 9.5.
  • the method further comprises adjusting a pH of the water to an alkaline pH (a pH according to any of the respective embodiments described herein) and subsequently passing through the water permeable composite membrane.
  • Adjusting the pH may optionally be effected by any suitable technique known in the art, including, for example, addition of a strong base (e.g., NaOH and/or KOH).
  • the method further comprises passing water through an additional water permeable composite membrane prior to or subsequent to passing the water through the water permeable composite membrane according to any of the respective embodiments described herein.
  • the additional water permeable composite membrane may optionally be a water permeable composite membrane according to any of the respective embodiments described herein, or alternatively, a composite membrane known in the art.
  • water is passed through a first water permeable composite membrane (e.g., an additional water permeable membrane) to thereby obtain a partially treated water, prior to passing the (partially treated) water through the water permeable composite membrane (according to any of the embodiments described herein) at an alkaline pH (according to any of the embodiments described herein), and optionally prior to adjusting the pH (according to any of the embodiments described herein) to the aforementioned alkaline pH.
  • a first water permeable composite membrane e.g., an additional water permeable membrane
  • the partially treated water is characterized by a decrease in salt concentration (relative to the salt concentration prior to passing through the first composite membrane), for example, a decrease of at least 50 %, at least 60 %, at least 70 %, at least 80 %, and optionally even at least 90 %.
  • the first water permeable composite membrane is optionally, but not necessarily, a composite membrane according to embodiments of the invention.
  • the method comprises passing water through the first water permeable composite membrane to thereby obtain a partially treated water (e.g., according to any of the respective embodiments described herein; adjusting a pH of the partially treated water to an alkaline pH (e.g., of at least 8), according to any of the respective embodiments described herein; and passing the partially treated water with alkaline pH through a second water permeable composite membrane which is a composite membrane according to any of the respective embodiments described herein.
  • a partially treated water e.g., according to any of the respective embodiments described herein
  • an alkaline pH e.g., of at least 8
  • passing the partially treated water through the second composite membrane decreases a boron concentration, by at least 20 %, optionally at least 50 %, optionally at least 60 %, optionally at least 70 %, optionally at least 80 %, and optionally by at least 90 %.
  • the water is passed through at least one water permeable composite membrane which comprises a degraded membrane restored according to a process described herein (e.g., according to any of the respective embodiments).
  • at least a composite membrane used at an alkaline pH e.g., according to any of the respective embodiments described herein
  • a second water permeable composite membrane described herein comprises a degraded membrane restored according to a process described herein (e.g., according to any of the respective embodiments).
  • a reverse osmosis apparatus comprising a water permeable composite membrane according to any of the respective embodiments described herein.
  • the reverse osmosis apparatus is optionally configured to treat water according to any of the respective embodiments described herein relating to a method of treating water.
  • the reverse osmosis apparatus is in communication with a reservoir for holding water prior to treatment via passage through the membrane, and/or a reservoir for collecting water treated via passage through the membrane.
  • the reverse osmosis apparatus is in a functional association with an apparatus configured applying a pressure difference between the water on each of the two sides of the membrane, for example, an apparatus configured for applying a greater than atmospheric pressure to the water on one side of the membrane (e.g., an elevated water reservoir and/or a pump) and/or an apparatus configured for applying a lower than atmospheric pressure to the water on the other side of the membrane (e.g., a pump configured for effecting suction).
  • alkyl refers to any saturated aliphatic hydrocarbon including straight chain and branched chain groups.
  • the alkyl group has 1 to 20 carbon atoms. Whenever a numerical range; e.g., "1-20", is stated herein, it implies that the group, in this case the alkyl group, may contain 1 carbon atom, 2 carbon atoms, 3 carbon atoms, etc., up to and including 20 carbon atoms. More preferably, the alkyl is a medium size alkyl having 1 to 10 carbon atoms. Most preferably, unless otherwise indicated, the alkyl is a lower alkyl having 1 to 4 carbon atoms.
  • the alkyl group may be substituted or non-substituted.
  • the substituent group can be, for example, cycloalkyl, aryl, heteroaryl, heteroalicyclic, halo, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, sulfinyl, sulfonyl, cyano, nitro, azide, phosphonyl, phosphinyl, oxo, carbonyl, thiocarbonyl, urea, thiourea, O-carbamyl, N-carbamyl, O-thiocarbamyl, N-thiocarbamyl, C-amido, N-amido, C- carboxy, O-carboxy, sulfonamido, and amino, as these terms are defined herein.
  • alkenyl describes an unsaturated aliphatic hydrocarbon comprise at least one carbon-carbon double bond, including straight chain and branched chain groups.
  • the alkenyl group has 2 to 20 carbon atoms. More preferably, the alkenyl is a medium size alkenyl having 2 to 10 carbon atoms. Most preferably, unless otherwise indicated, the alkenyl is a lower alkenyl having 2 to 4 carbon atoms.
  • the alkenyl group may be substituted or non-substituted.
  • Substituted alkenyl may have one or more substituents, whereby each substituent group can independently be, for example, cycloalkyl, alkynyl, aryl, heteroaryl, heteroalicyclic, halo, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, sulfinyl, sulfonyl, cyano, nitro, azide, phosphonyl, phosphinyl, oxo, carbonyl, thiocarbonyl, urea, thiourea, O-carbamyl, N- carbamyl, O-thiocarbamyl, N-thiocarbamyl, C-amido, N-amido, C-carboxy, O-carboxy, sulfonamido, and amino.
  • substituent group can independently be, for example, cycloalkyl, alkynyl, aryl,
  • alkynyl describes an unsaturated aliphatic hydrocarbon comprise at least one carbon-carbon triple bond, including straight chain and branched chain groups.
  • the alkynyl group has 2 to 20 carbon atoms. More preferably, the alkynyl is a medium size alkynyl having 2 to 10 carbon atoms. Most preferably, unless otherwise indicated, the alkynyl is a lower alkynyl having 2 to 4 carbon atoms.
  • the alkynyl group may be substituted or non-substituted.
  • Substituted alkynyl may have one or more substituents, whereby each substituent group can independently be, for example, cycloalkyl, alkenyl, aryl, heteroaryl, heteroalicyclic, halo, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, sulfinyl, sulfonyl, cyano, nitro, azide, phosphonyl, phosphinyl, oxo, carbonyl, thiocarbonyl, urea, thiourea, O-carbamyl, N- carbamyl, O-thiocarbamyl, N-thiocarbamyl, C-amido, N-amido, C-carboxy, O-carboxy, sulfonamido, and amino.
  • substituent group can independently be, for example, cycloalkyl, alkenyl, aryl, hetero
  • a "cycloalkyl” group refers to a saturated on unsaturated all-carbon monocyclic or fused ring (i.e., rings which share an adjacent pair of carbon atoms) group wherein one of more of the rings does not have a completely conjugated pi-electron system.
  • examples, without limitation, of cycloalkyl groups are cyclopropane, cyclobutane, cyclopentane, cyclopentene, cyclohexane, cyclohexadiene, cycloheptane, cycloheptatriene, and adamantane.
  • a cycloalkyl group may be substituted or non- substituted.
  • the substituent group can be, for example, alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heteroaryl, heteroalicyclic, halo, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, sulfinyl, sulfonyl, cyano, nitro, azide, phosphonyl, phosphinyl, oxo, carbonyl, thiocarbonyl, urea, thiourea, O-carbamyl, N- carbamyl, O-thiocarbamyl, N-thiocarbamyl, C-amido, N-amido, C-carboxy, O-carboxy, sulfonamido, and amino, as these terms are defined herein.
  • a cycloalkyl group When a cycloalkyl group is unsaturated, it may comprise at least one carbon
  • aryl group refers to an all-carbon monocyclic or fused-ring polycyclic (i.e., rings which share adjacent pairs of carbon atoms) groups having a completely conjugated pi-electron system. Examples, without limitation, of aryl groups are phenyl, naphthalenyl and anthracenyl. The aryl group may be substituted or non-substituted.
  • the substituent group can be, for example, alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heteroaryl, heteroalicyclic, halo, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, sulfinyl, sulfonyl, cyano, nitro, azide, phosphonyl, phosphinyl, oxo, carbonyl, thiocarbonyl, urea, thiourea, O-carbamyl, N- carbamyl, O-thiocarbamyl, N-thiocarbamyl, C-amido, N-amido, C-carboxy, O-carboxy, sulfonamido, and amino, as these terms are defined herein.
  • heteroaryl group refers to a monocyclic or fused ring (i.e., rings which share an adjacent pair of atoms) group having in the ring(s) one or more atoms, such as, for example, nitrogen, oxygen and sulfur and, in addition, having a completely conjugated pi-electron system.
  • heteroaryl groups include pyrrole, furan, thiophene, imidazole, oxazole, thiazole, pyrazole, pyridine, pyrimidine, quinoline, isoquinoline and purine.
  • the heteroaryl group may be substituted or non- substituted.
  • the substituent group can be, for example, alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heteroaryl, heteroalicyclic, halo, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, sulfinyl, sulfonyl, cyano, nitro, azide, phosphonyl, phosphinyl, oxo, carbonyl, thiocarbonyl, urea, thiourea, O-carbamyl, N- carbamyl, O-thiocarbamyl, N-thiocarbamyl, C-amido, N-amido, C-carboxy, O-carboxy, sulfonamido, and amino, as these terms are defined herein.
  • heteroalicyclic group refers to a monocyclic or fused ring group having in the ring(s) one or more atoms such as nitrogen, oxygen and sulfur.
  • the rings may also have one or more double bonds. However, the rings do not have a completely conjugated pi-electron system.
  • the heteroalicyclic may be substituted or non- substituted.
  • the substituted group can be, for example, alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heteroaryl, heteroalicyclic, halo, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, sulfinyl, sulfonyl, cyano, nitro, azide, phosphonyl, phosphinyl, oxo, carbonyl, thiocarbonyl, urea, thiourea, O-carbamyl, N- carbamyl, O-thiocarbamyl, N-thiocarbamyl, C-amido, N-amido, C-carboxy, O-carboxy, sulfonamido, and amino, as these terms are defined herein.
  • Representative examples are piperidine, piperazine, tetrahydrofuran, tetrahydropyran,
  • alkoxy refers to both an -O-alkyl and an -O-cycloalkyl group, as defined herein.
  • aryloxy refers to both an -O-aryl and an -O-heteroaryl group, as defined herein.
  • a "hydroxy” group refers to a -OH group.
  • a “thiohydroxy” or “thiol” group refers to a -SH group.
  • a “thioalkoxy” group refers to both an -S-alkyl group, and an -S-cycloalkyl group, as defined herein.
  • a "thioaryloxy” group refers to both an -S-aryl and an -S-heteroaryl group, as defined herein.
  • a “carboxyl”, “carboxylic” or “carboxylate” refers to both “C-carboxy” and O- carboxy”.
  • halo refers to fluorine, chlorine, bromine or iodine.
  • a “sulfonamide” or “sulfonamido” group encompasses both S-sulfonamido and N-sulfonamido groups, as defined herein.
  • a “carbamyl” or “carbamate” group encompasses O-carbamyl and N-carbamyl groups.
  • a "thiocarbamyl” or “thiocarbamate” group encompasses O-thiocarbamyl and
  • a “nitro” group refers to an -NO2 group.
  • a “cyano” group refers to a -C ⁇ N group.
  • phosphinyl describes a -PR'R" group, with each of R' and R" as defined hereinabove.
  • the term “about” refers to ⁇ 20 %. In some embodiments of any of the embodiments described herein using the term “about”, the term “about” is to be interpreted as ⁇ 10 %.
  • compositions, method or structure may include additional ingredients, steps and/or parts, but only if the additional ingredients, steps and/or parts do not materially alter the basic and novel characteristics of the claimed composition, method or structure.
  • a compound or “at least one compound” may include a plurality of compounds, including mixtures thereof.
  • range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.
  • PA membranes SWC5 max and SWC4B (Hydranautics) were obtained from Hydranautics, and stored as described by Bernstein et al. [Langmuir 2010, 26: 12358-12365].
  • the membrane characteristics as specified by the manufacturer - for spiral-wound elements of nominal membrane area 400 ft 2 tested using feed solution of 32,000 ppm NaCl, 5 ppm boron, pH 6.5-5 at applied pressure 55 bar and 10% recovery - were as follows:
  • SWC5 max boron rejection 92 %, salt rejection 99.8 %, flow rate 37.5 m 3 /day;
  • SWC4B boron rejection 95 %, salt rejection 99.8 %, flow rate 24.6 m 3 /day.
  • C p and C/ are the permeate and feed concentrations, respectively.
  • Attenuated total reflection Fourier transform infra-red (ATR-FTIR) spectra were recorded (average of 40 scans at 4 cm "1 resolution) on a NicoletTM 8700 FTIR spectrometer (Thermo -Electron) using a Miracle ATR attachment with a one-reflection diamond-coated KRS-5 element (Pike).
  • the bands of interests were those of polyamide and polysulfone (at 1660 cm “1 and 1586 cm “1 , respectively) of the pristine membrane and the aliphatic CH bands in the region of 2,800-3,000 cm “1 that represent the IR absorption of the modifying molecules (aliphatic amines).
  • EDC electrospray diffraction
  • treatment of the polyamide membrane with any of the amine-containing compounds reduced water permeability of the membrane.
  • NaCl rejection was also enhanced by treatment with amine- containing compounds, although to a lesser degree than boron rejection enhancement (data not shown).
  • Tert-octylamine exhibited the highest MPA among the tested amine-containing compounds (about 32 A 2 , as opposed to about 18-27 A 2 for the other compounds), but does not exhibit an exceptional LogP or molecular volume in comparison with the other tested compounds. This result suggests that the relatively large molecular width and/or MPA of compounds such as tert-octylamine result in a considerably reduced ability to penetrate nano-pores, thereby having less of an effect on boron permeability.
  • Phenethylamine which differs from the other amine-containing compounds in that it is aromatic, did not enhance rejection, similarly to the aliphatic amines (data not shown). Indeed, rejection of NaCl and boron often decreased after modification with phenethylamine. Moreover, treatment with relatively high concentrations of phenethylamine resulted in visible damage to the membrane, suggesting that the polysulfone layer was affected.
  • aromatic amines do not significantly alter the chemistry around pores, possibly because they are too similar in structure to the unmodified aromatic polyamide and/or because of their considerable polarizability.
  • the greater width of aromatic amines versus linear aliphatic amines may also limit the ability of aromatic amines to enter and interact with pores.
  • ATR-FTIR spectroscopy was used to directly detect the uptake of aliphatic amines.
  • uptake of dodecylamine resulted in larger aliphatic C-H stretching bands than did uptake of propylamine, which is consistent with the larger size and greater hydrophobicity of the dodecylamine aliphatic moiety in comparison with the propylamine aliphatic moiety.
  • the ATR-FTIR spectrum did not change significantly after a 48 hour wash, during which the membranes were soaked in hot boiled water at 60 °C with water exchanged several times (data not shown). These results indicate that the amine- containing compound was strongly bound to the polyamide membrane, confirming the formation of amide bonds.
  • the spectrum upon aliphatic amine uptake was not much affected in spectral regions other than the 2800-3000 cm "1 region.
  • An exception was a small band which emerged at 1720 cm "1 , which was assigned to the carbonyl group of an ionized carboxylic group of polyamide.
  • Uptake of decylamine and dodecylamine was also detected by measuring water contact angles of the membranes before and after treatment.
  • the water contact angle of untreated SWC4B membranes was 42.0° + 2.4°, whereas the water contact angle of SWC4B membranes treated with decylamine was 54.3° + 1.9° and the water contact angle of SWC4B membranes treated with dodecylamine was 51.1° + 2.3°.
  • RO polyamide membrane SWC4B membrane
  • SWC4B membrane An RO polyamide membrane (SWC4B membrane) was mounted in a dead end cell and tested for performance.
  • the cell was then filled with a solution of a tested amine-containing compound, and the solution was filtered for about an hour at a pressure of 55 bar.
  • the solution was then removed and the system was washed with DDW without dissembling the cell, soaked in DDW for 24 hours, and then examined again for boron and NaCl rejection and permeability.
  • the above procedure does not promote covalent binding of the amine-containing compounds to the membrane, but does allow formation of ionic bonds between positively charged amine groups and negatively charged carboxylic groups, as well as physical sorption (e.g., by hydrophobic interactions).
  • any type of membrane can be modified so as to simultaneously increase or reduce solute passage and water permeability - for example, by adjusting the effective thickness of the membrane - RO membranes may generally be characterized by a tradeoff between selectivity (associated with effective removal of solutes) and flux (associated with water permeability).
  • a successful modification of a membrane may be characterized by an improved flux-selectivity tradeoff.
  • modified membranes exhibited a ratio of boron passage to water permeability (in the presence of 32,000 ppm NaCl and 5 ppm boron) which was similar to or reduced in comparison to unmodified commercial SWC5 max and SWC4B membranes.
  • the improvement in boron rejection relative to water permeability was greatest for the longest tested alkylamines (e.g., decylamine and dodecylamine), which reduced the ratio of boron passage to water permeability considerably upon either covalent binding or adsorption, as well as for a branched alkylamine (2-methyl-butylamine) having an almost identical MPA.
  • the improvement in boron rejection relative to water permeability was usually greater for covalently bound alkylamines than for adsorbed alkylamines.
  • Fully aromatic polyamide (PA) membrane spiral-wound FilmtecTM SW30-2540 elements of nominal membrane area 2.8 m 2 were obtained from Dow and stored according to the manufacturer's recommendations.
  • the membrane characteristics as specified by the manufacturer were as follows: boron rejection 91 %, salt rejection 99.4 %, flow rate 2.6 m 3 /day.
  • FIG. 8 In situ modification of spiral wound membrane elements and the filtration experiments were performed in a pilot unit depicted schematically in FIG. 8.
  • the setup included a 200 liter feed tank, a 2540 membrane element mounted in a stainless steel pressure vessel (M-1), a high pressure pump with an auxiliary feed pump, a feed pressure gauge (PI-1) and a control valve with a pressure gauge located in the concentrate line (PI-2).
  • the water fluxes were monitored using flow-meters installed in the feed and permeate lines.
  • the water temperature was controlled and monitored using a heat exchanger (HE-1) equipped with a thermometer.
  • the system was operated in a closed loop returning the permeate and concentrate back to the feed tank. Filtration tests were performed on the RO pilot system depicted schematically in FIG. 8.
  • a FilmtecTM SW30 RO membrane was mounted in the RO system and initial performance was tested, as follows. First, the membrane was compacted at 20 bar for 2 hours and the pure water permeability was measured at feed pressure of 40 bar and concentrate flow of 500 liters/hour. Pure water was then replaced with a solution of 15,000 ppm NaCl and 5 ppm boron (in the form of added boric acid) at pH 7-7.3; and the membrane performance, including NaCl and B rejection and volumetric flux, was tested at a feed pressure of 40 bar, keeping the recovery in the range 13-16 %.
  • Permeate and feed samples were collected and measured every 30 minutes before modification and after washing stage followed the modification.
  • the permeability was determined according to the formula:
  • V is the permeate volume collected over time t
  • A is the membrane surface area in the element as reported by the manufacturer (2.8 m 2 )
  • P is the applied transmembrane pressure difference
  • ⁇ is the osmotic pressure difference which was calculated using the van 't Hoff equation.
  • the membrane was treated using solutions of one of the aliphatic amine molecules at concentrations of 0.1, 0.5, 1 and 2 mM, in order to effect sorption of the amine.
  • concentrations 0.1, 0.5, 1 and 2 mM
  • For each element modifying solutions of a specific amine were applied starting from lowest concentration (0.1 mM) up to the highest concentration (2 mM).
  • the system was washed with pure water and performance of the membrane was tested as described hereinabove.
  • decylamine considerably enhanced membrane selectivity in a concentration-dependent manner at all concentrations tested (up to 2 mM, which is below the water solubility of decylamine (3.5 mM)), with boron passage being reduced to a greater extent (from about 9-10 % to about 2 %) than water permeability.
  • dodecylamine considerably decreased membrane boron passage in a concentration-dependent manner up to a concentration of 1 mM, from about 9-10 % to about 5 %.
  • a portion of the dodecylamine in the solution may be in the form of micelles (which may potentially foul the membrane by depositing on the membrane surface), and increasing the concentration from 1 mM to 2 mM may add to the micelle phase without altering the concentration of free molecules.
  • amylamine and n-octylamine had little effect on boron passage or water permeability (data not shown), suggesting that the solubility of these alkylamines was too high to result in significant partitioning to the polyamide in this setup and/or that the lower hydrophobicity of the alkylamines was insufficient to alter polyamide properties significantly.
  • salt passage was not significantly effected by any of the tested alkylamines at concentrations in the range of 0.1 to 2 mM.
  • the modules were cut open and membrane samples were taken from different parts of the module for surface characterization.
  • ATR-FTIR was used to directly detect the uptake of aliphatic amines, according to procedures described in the Materials and Methods section hereinabove.
  • dodecylamine and dodecylamine uptake were observed as similar aliphatic C-H stretching bands emerging in the 2800-3000 cm “1 region, in which aromatic polyamide and polysulfone support have little or no IR absorption.
  • the IR spectrum did not show significant changes in regions other than 2800-3000 cm "1 , indicating that the membrane was not damaged or chemically altered.
  • modified polyamide membrane surfaces exhibited the characteristic ridge-and-valley morphology of pristine polyamide membrane surfaces, indicating that the morphology of the polyamide top-layer was unaffected by modification.
  • RO membranes in general show a correlation between boron passage and water permeability, i.e., born rejection is enhanced when membranes are less permeable, the significance of modification was evaluated on a tradeoff plot, showing both boron passage and water permeability.
  • Hydrolysis in polyamide membranes may occur upon exposure to alkaline solutions. Although manufacturer's commonly claim that membrane performance is not affected between a pH 1-2 and a pH of 10-11, relevant data is scarce.
  • brackish water reverse osmosis (BWRO) membranes operating at a second pass of a commercial seawater desalination plant, after exposure to a relatively high pH (pH > 9) for several months.
  • the high pH is used to ionize boric acid, to thereby facilitate boron removal in the second pass, after seawater has been converted to brackish water in the first pass.
  • BW30 membranes (Dow) were exposed to NaOH solutions with pH 11 for 24 hours, followed by a wash with distilled water.
  • the characteristics of the pristine BW30 membrane as specified by the manufacturer were as follows: boron rejection 65 %, salt rejection 99.5 %, flow rate 40.08 m 3 /day.
  • Membranes pre-treated at pH 11 in this manner served as a model for membranes damaged by months of use at more moderately alkaline conditions.
  • the membrane was mounted in a dead end cell and tested for initial performance (boron passage, salt passage, and water flux) was tested at a pH in a range of 7.0 to 7.3, using procedures described hereinabove.
  • hexadecylamine treatment by covalent coupling (FIG. 15A) or by sorption (FIG. 15B) reversed the hydrolysis-induced increase in salt passage and boron passage, by reducing salt passage and boron passage levels even lower than of those of a pristine membrane.

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Abstract

A water permeable composite membrane is disclosed herein, comprising a thin film layer on a porous substrate. The thin film comprises a polymer and amine - containing compound associated with the polymer, and the amine-containing compound comprises at least one aliphatic hydrocarbon moiety attached to an amine group. Further disclosed herein are a process for preparing the aforementioned composite membrane described herein, a reverse osmosis apparatus comprising said composite membrane, and a method utilizing said composite membrane for treating water.

Description

MODIFIED POLYAMIDE MEMBRANES
FIELD AND BACKGROUND OF THE INVENTION
The present invention, in some embodiments thereof, relates to membranes for reverse osmosis, and more particularly, but not exclusively, to membranes which efficiently remove boron from water, to articles containing same and to uses thereof.
Synthetic membranes for separation are used in many industrial applications, including water treatment. Membranes are used for filtration of potable water, treatment of industrial and municipal waste water, and for desalination of brackish water and seawater.
Reverse osmosis (RO) membrane desalination has become one of the main desalination techniques, estimated as providing 44 % of the total volume of desalinated water in the world, and its use is expected to grow in the coming years [Greenlee et al., Water Res 2009, 43:2317-2348]. RO is a pressure-driven process whereby a semipermeable membrane (i.e., RO membrane) rejects dissolved constituents in the feeding water but allows water to pass through. RO technology is greatly dependent on the development of RO membranes, as the membrane plays a key role in technological and economic efficiency of the RO process [Loeb & Sourirajan, Adv Chemistry 1962, 38:117-132].
Thin-film composite (TFC) membranes with a polyamide top layer are the most common type of RO membranes used nowadays. These membranes are composed of three distinct layers on top of each other. The top layer is a thin, dense, non-porous aromatic or semi-aromatic polyamide active layer, is typically 20 to 200 nm thick and provides the separation selectivity [Petersen, J Membr Sci 1993, 83:81-150]. The top layer is typically deposited on a porous layer of polyethersulfone or polysulfone which is on top of a non-woven fabric support sheet.
The polyamide top layer is typically prepared by interfacial polymerization of an aromatic triacid and diamine. The top layer thus typically contains some unreacted, mainly acidic carboxylic acid, groups within the membrane and on the surface. Compared with older-type cellulosic membranes, the TFC aromatic polyamide membrane exhibits superior water flux and salt rejection, resistance to pressure compaction, wider operating temperature range and pH range, and higher stability to biological attack [Li & Wang, Materials Chem 2010, 20:4551-4566]. However, a major limitation of such membranes is the relatively poor removal of small uncharged molecules such as boric acid.
Seawater contains boron (in the form of boric acid) at concentrations of 4-7 ppm. Although its toxicity to humans is low, the World Health Organization recommended guideline for maximum boron concentration in potable water is 0.5 ppm [Bernstein et al., Environ Sci Technol 2011, 45:3613-3620]. Furthermore, although boric acid is an essential micronutrient for plants, it becomes toxic to plants at concentrations above 0.5- 1 ppm (depending on their boron tolerance) [Tang et al., J Membr Sci 2007, 290:86-94]. Therefore, the recommended maximal boron concentration for desalinated water which may be used for irrigation is 0.3-0.5 ppm. For achieving such a boron concentration by RO of seawater or brackish water, an average boron rejection of over 90 % is required. However, as commonly used seawater RO and brackish water RO polyamide membranes typically exhibit boron rejection in ranges of 80-93 % and 30-80 %, respectively, a single -pass RO process is usually unable to remove enough boron to reach the recommended boron concentration, and multiple passes are required.
Boric acid is a weak acid with pKai of about 8.6-9.2 in seawater [Hansson, Deep-Sea Res 1973, 20:461-478]. As most feeds used in desalination have a pH in a range of 7.5-8 [Redondo et al., Desalination 2003, 156:229-238], boric acid in seawater is mainly undissociated and its passage through RO membranes is affected mainly by size exclusion and hindrance (molecular friction). These factors however are not sufficiently strong because the B(OH)3 molecule is small.
Uncharged boric acid has a molecular diameter of 2.75 A, and its Stokes radius is only about 1.55 A, as calculated from the diffusion coefficient 1.41 x 10"9 m2/s in water at pH 7 [Park & Lee, Chem Eng Data 1994, 39:891-894]. Thus, boric acid is significantly smaller than hydrated sodium (3.58 A) and chloride (3.32 A) ions, rendering removal of boron considerably more difficult than removal of sodium chloride. The same conclusion is reached when using other metrics of molecule size, such as molecular width [Kiso et al., J Membr Sci 2001, 192:1-10] and minimum projection area (MPA) [Fujioka et al., Membr Sci 2015, 486: 106-118], which have been reported to better correlate with passage of solutes through membranes than do molecular weight or volume. In addition, hydrogen bonding between the hydroxyl groups of boric acid and water within a RO membrane may enhance association and drag of boric acid by water, and facilitate passage of boric acid through the membrane [Sagiv & Semiat, J Membr Sci 2004, 243:79-87].
Rejection of boric acid by commercially available RO membranes has been reported to show a good correlation to the mean free-volume hole radius of the membranes [Fujioka et al., Membr Sci 2015, 486: 106-118]. TFC polyamide RO membranes have been reported to have a bimodal distribution of pore size with two types of pores, network pores having radii of about 1-3 A, and aggregate pores, having radii of about 3.5-4.5 A. As the radius of uncharged boric acid (2.75 A) is close to that of the network pores and substantially less than that of the aggregated pores, boric acid can penetrate the pore network of RO membranes [U.S. Patent No. 8,616,380].
Boron removal can be improved by various pre- and post-treatment techniques [Xu & Jiang,. Ind Eng Chem Res 2008, 47: 16-24] and by double -pass RO. Faigon & Hefer [Desalination 2008, 223:10-16] describe a four-stage process for reducing boron concentration. However, additional treatment steps increase the energy consumption and water cost substantially.
U.S. Patent No. 6,296,773 describes a process for reducing boron and fluoride ion content of water by using magnesium to precipitate boron and fluoride.
U.S. Patent No. 8,236,180 describes a method of removing boron from water by using an amide derivative under alkaline conditions to cause adsorption of boron to the amide derivative, followed by addition of a cation to cause aggregation of the amide body.
U.S. Patent No. 7,279,097 describes a composite semipermeable membrane having a high rejection performance for salt and non-dissociative substances such as boric acid, wherein a monofunetional amine binds to and/or adsorbs to the inside and/or surface of the membrane, and/or wherein an aliphatic acyl group binds to the inside and/or surface of a separating functional layer.
Bernstein et al. [Environ Sci Technol 2011, 45:3613-3620] discusses the contribution of hydrophobicity and steric exclusion (e.g., smaller pore size) towards rejection of boron, and describes modification of low pressure RO membranes by graft polymerization of glycidyl methacrylate, resulting in a membrane with a relatively high permeability characteristic of brackish water RO, but with removal of boric acid and salt superior to those of most commercial brackish water RO membranes.
U.S. Patent No. 5,755,964 describes a one-step process for enhancing the flux of a composite reverse osmosis or nanofiltration membrane while substantially maintaining the NaCl rejection rate, in which the discriminating layer is contacted with ammonia or certain alkylamines.
Additional background art includes Ben David et al. [ Membr Sci 2010, 357: 152-159], Drazevic et al. [Environ Sci Technol 2012, 46:3377-3383], Kato et al. [Prog Polymer Sci 2003, 28:209-259], Khulbe et al. [J Appl Polym Sci 2010, 115:855- 895], Kurihara et al. [Desalination 2015, 368: 135-139], Pinnau & Freeman ["Formation and modification of polymeric membranes: overview", in Membrane Formation and Modification, pp. 1-22. ACS Symposium Series 744. American Chemical Society: Washington DC, 2000], Rana & Matsuura [Chem Rev 2010, 110:2448-2471], Strathmann & Michaels [Desalination 1977, 21: 195-202], Ulbricht [Polymer 2006, 47:2217-2262], Van der Bruggen & Vandecasteele [Environ Sci Technol 2001, 35:3535- 3540], Williams et al. [Ind Eng Chem Res 1999, 38:3683-3695], Japanese Patent Application Publication No. 02-002827 (also published as Japanese Patent No. 2682071), US Patent No. 8,616,380, and Zeman & Zydney [Microfiltration and ultrafiltration: Principles and applications. Marcel Dekker: New York, NY, 1996]. SUMMARY OF THE INVENTION
According to an aspect of some embodiments of the invention, there is provided a water permeable composite membrane comprising a thin film layer on a porous substrate, the thin film comprising a polymer and amine-containing compound associated with the polymer, the amine-containing compound comprising at least one aliphatic hydrocarbon moiety attached to an amine group.
According to an aspect of some embodiments of the invention, there is provided a process for preparing the water permeable composite membrane described herein, the process comprising contacting a thin film layer comprising the polymer with the amine- containing compound. According to an aspect of some embodiments of the invention, there is provided a reverse osmosis apparatus comprising the water permeable composite membrane described herein.
According to an aspect of some embodiments of the invention, there is provided a method of treating water, the method comprising passing water with solutes through the water permeable composite membrane described herein, thereby treating the water.
According to some embodiments of the invention, the polymer comprises a poly amide.
According to some embodiments of the invention, the aliphatic hydrocarbon moiety is from 1 to 30 carbon atoms in length, being saturated or unsaturated, and substituted or unsubstituted.
According to some embodiments of the invention, the aliphatic hydrocarbon moiety is at least 3 carbon atoms in length.
According to some embodiments of the invention, the aliphatic hydrocarbon moiety contains at least 8 carbon atoms.
According to some embodiments of the invention, the amine-containing compound has the general formula:
Figure imgf000007_0001
wherein:
Ri is the aliphatic hydrocarbon moiety; and
R2 and R3 are each independently selected from the group consisting of hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, and a heteroalicyclic, or, alternatively, one or both of R2 and R3 is independently a covalent bond linking the amine-containing compound to the polymer or a group participating in a covalent bond linking the amine- containing compound to the polymer.
According to some embodiments of the invention, the amine-containing compound is associated with the polymer via an amide bond to the polymer. According to some embodiments of the invention, at least one of R2 and R3 is a covalent bond linking the amine-containing compound to the polymer or a group participating in a covalent bond linking the amine-containing compound to the polymer.
According to some embodiments of the invention, R2 and/or R3 is an amide bond with a carboxylic group in the polymer.
According to some embodiments of the invention, R2 is hydrogen and R3 is an amide bond described herein.
According to some embodiments of the invention, the amine-containing compound is associated with the polymer via non-covalent interactions.
According to some embodiments of the invention, R2 and R3 are each independently selected from the group consisting of hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, and a heteroalicyclic.
According to some embodiments of the invention, R2 and R3 are each hydrogen.
According to some embodiments of the invention, the aliphatic hydrocarbon moiety is at least 5 carbon atoms in length.
According to some embodiments of the invention, Ri is at least 8 carbon atoms in length.
According to some embodiments of the invention, Ri consists of a linear aliphatic hydrocarbon moiety which is unsubstituted or is substituted by one or more substituents selected from the group consisting of alkyl, alkenyl, alkynyl, cycloalkyl, heteroalicyclic, halo, hydroxy, alkoxy, thiohydroxy, thioalkoxy, sulfinyl, sulfonyl, cyano, nitro, azide, phosphonyl, phosphinyl, oxo, carbonyl, thiocarbonyl, urea, thiourea, O-carbamyl, N-carbamyl, O-thiocarbamyl, N-thiocarbamyl, C-amido, N-amido, C- carboxy, O-carboxy, sulfonamido, and amino.
According to some embodiments of the invention, when the linear aliphatic hydrocarbon is substituted, each of the one or more substituents is no more than 3 atoms in length.
According to some embodiments of the invention, the one or more substituents are each independently selected from the group consisting of methyl, halo, hydroxy, thiohydroxy, oxo, and -NH2.
According to some embodiments of the invention, the one or more substituents are selected from the group consisting of alkyl, alkenyl, alkynyl, cycloalkyl, and halo. According to some embodiments of the invention, the linear aliphatic hydrocarbon moiety is substituted by no more than two substituents.
According to some embodiments of the invention, the linear aliphatic hydrocarbon moiety is substituted by no more than one substituent.
According to some embodiments of the invention, the linear aliphatic hydrocarbon moiety comprises no more than one substituent attached to each carbon atom in the linear aliphatic hydrocarbon moiety.
According to some embodiments of the invention, a LogP of the amine- containing compound is at least 0.2.
According to some embodiments of the invention, a LogP of the amine- containing compound is at least 1.0.
According to some embodiments of the invention, a LogP of the amine- containing compound is no more than 6.0.
According to some embodiments of the invention, a minimum projection area of the amine-containing compound is no more than 30 A2.
According to some embodiments of the invention, a minimum projection area of the amine-containing compound is at least 18 A2.
According to some embodiments of the invention, a boron passage rate of the composite membrane is less than 80 % of a boron passage rate of a corresponding composite membrane without the amine-containing compound covalently and/or non- covalently bound to the polymer, wherein the boron passage rate is determined using an aqueous solution of boric acid and NaCl with 32,000 ppm NaCl and 5 ppm boron, at pH 7, and at a feed pressure of 55 bar.
According to some embodiments of the invention, a water permeability of the composite membrane is at least 20 % of a water permeability of a corresponding composite membrane without the amine-containing compound covalently and/or non- covalently bound to the polymer, wherein the water permeability is determined using an aqueous solution of boric acid and NaCl with 32,000 ppm NaCl and 5 ppm boron, at pH 7, and at a feed pressure of 55 bar.
According to some embodiments of the invention, a boron passage rate of the composite membrane is less than 20 %, wherein the boron passage rate is determined using an aqueous solution of boric acid and NaCl with 32,000 ppm NaCl and 5 ppm boron, at pH 7, and at a feed pressure of 55 bar.
According to some embodiments of the invention, a water permeability of the composite membrane is at least 0.2 liters per square meter per bar per hour (l-m~2-bar~ ^hour"1), wherein the water permeability is determined using an aqueous solution of boric acid and NaCl with 32,000 ppm NaCl and 5 ppm boron, at pH 7, and at a feed pressure of 55 bar.
According to some embodiments of the invention, a ratio of a boron passage rate to water permeability of the composite membrane is less than 90 % of a ratio of a boron passage rate to water permeability of a corresponding composite membrane without the amine-containing compound covalently and/or non-covalently bound to the polymer, wherein the boron passage rate and the water permeability are determined using an aqueous solution of boric acid and NaCl with 32,000 ppm NaCl and 5 ppm boron, at pH 7, and at a feed pressure of 55 bar.
According to some embodiments of the invention, a ratio of a boron passage rate to water permeability of the composite membrane is less than 30 % boron passage rate per 1.0 liter per square meter per bar per hour water permeability (30 % per l-m"2-bar" ^hour"1), wherein the boron passage rate and the water permeability are determined using an aqueous solution of boric acid and NaCl with 32,000 ppm NaCl and 5 ppm boron, at pH 7, and at a feed pressure of 55 bar.
According to some embodiments of the invention, the polymer comprises free carboxylic acid groups, and the process described herein further comprising contacting the thin film layer with an activator of carboxylic acid groups, the activator being selected as being capable of forming an amide bond between carboxylic acid groups and amine groups.
According to some embodiments of the invention, a ratio of free carboxylic acid groups to amide groups in the polymer prior to contacting the thin film layer with the activator of carboxylic acid groups is in a range of from 1:50 to 1: 1 (free carboxylic acid: amide).
According to some embodiments of the invention, the contacting described herein is effected using a solution of the amine-containing compound, wherein a concentration of the amine-containing compound in the solution is selected such that a water permeability of the composite membrane is at least 0.2 liters per square meter per bar per hour (l-m ^bar ^hour 1), wherein the water permeability is determined using an aqueous solution of boric acid and NaCl with 32,000 ppm NaCl and 5 ppm boron, at pH 7, and at a feed pressure of 55 bar.
According to some embodiments of the invention, the thin film layer is degraded following use thereof to treat water, the process described herein being for at least partially restoring the degraded thin film layer.
According to some embodiments of the invention, the thin film layer is degraded following use thereof at a pH of at least 8.
According to some embodiments of the invention, treating the water as described herein comprises reducing a concentration of boron in the water to less than 0.5 ppm.
According to some embodiments of the invention, passing the water through the water permeable composite membrane as described herein is effected no more than once.
According to some embodiments of the invention, the water with solutes has a pH of at least 8.
According to some embodiments of the invention, the method comprises:
passing water with solutes through a first water permeable composite membrane, to thereby obtain a partially treated water;
adjusting a pH of the partially treated water to at least 8, to thereby obtain the water with solutes having a pH of at least 8; and
passing the water with solutes having a pH of at least 8 through a second water permeable composite membrane which is a water permeable composite membrane according to any one of the respective embodiment described herein,
thereby treating the water.
Unless otherwise defined, all technical and/or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the invention, exemplary methods and/or materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
Some embodiments of the invention are herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of embodiments of the invention. In this regard, the description taken with the drawings makes apparent to those skilled in the art how embodiments of the invention may be practiced.
In the drawings:
FIG. 1 is a depiction of the structure of a polyamide in the top layer of a commercially available thin-film composite membrane (free amine group and free carboxylic acid group are circled).
FIG. 2 presents a bar graph showing water flux through polyamide membranes treated with 15.64 mM propylamine, butylamine, 2-methyl-butylamine or tert- octylamine, or with 1.04 mM amylamine, hexylamine, decylamine or dodecylamine, following activation of the membrane with EDC (testing conditions: 55 bar).
FIG. 3 presents a bar graph showing the boron passage of polyamide membranes treated with propylamine, butylamine, 2-methyl-butylamine, amylamine, hexylamine, tert-octylamine, decylamine or dodecylamine, following activation of the membrane with EDC (testing conditions: 5 ppm boron, 32,000 ppm NaCl, pressure 55 bar; each bar represents average of at least 4 results).
FIG. 4 presents a graph showing boron rejection (defined as 100 % minus boron passage in %) of polyamide membranes treated with an amine containing compound (propylamine, butylamine, 2-methyl-butylamine, amylamine, hexylamine, tert- octylamine, decylamine or dodecylamine) as a function of the minimum projection area (MPA) of the amine-containing compound (testing conditions: 5 ppm boron, 32,000 ppm NaCl, pressure 55 bar; data point for tert-octylamine is circled).
FIG. 5 presents an ATR-FTIR (attenuated total reflectance Fourier transform infra-red) spectrum of a pristine polyamide membrane (dashed line) and a polyamide membrane modified by amidation with EDC and propylamine (dotted line) or dodecylamine (solid line) (aliphatic C-H stretching bands are in 2800-3000 cm"1 region).
FIG. 6 presents a bar graph showing the boron passage of SWC4B polyamide membranes before and after modification of the membrane with amylamine, hexylamine, decylamine or dodecylamine (testing conditions: 5 ppm boron, 32,000 ppm NaCl, pressure 55 bar; each bar represents average of at least 4 results).
FIG. 7 presents a graph showing boron passage of polyamide membranes as a function of water permeability of the membrane in a dead-end cell, for unmodified SWC5max and SWC4B polyamide membranes, SWC5max membranes treated with carbodiimide and propylamine (C3 circle), butylamine (C4 circle), 2-methyl-butylamine (C5* circle), amylamine (C5 circle), hexylamine (C6 circle) or tert-octylamine (C8* circle), and SWC4B membranes treated with carbodiimide and decylamine (CIO circle) or dodecylamine (C12 circle), or treated with amylamine (C-5 triangle), hexylamine (C6 triangle), decylamine (CIO triangle) or dodecylamine (C-12 triangle) without a carbodiimide (testing conditions: 5 ppm boron, 32,000 ppm NaCl, pressure 55 bar; each data point average represents at least 4 results).
FIG. 8 is a scheme depicting an apparatus for treating and testing a multi- membrane element according to some embodiments of the invention; the apparatus comprises a feed tank, a multi-membrane element mounted in a stainless steel pressure vessel (M-l), a high pressure pump with an auxiliary feed pump, a feed pressure gauge (PI-1), a control valve with a pressure gauge located in the concentrate line (PI-2), a heat exchanger (HE-1) equipped with a thermometer configured controlling and monitoring water temperature, and a tank drainage valve (D-l).
FIGs. 9A and 9B present graphs showing boron passage and water flux through membranes of an SW30-2450 element before (pristine) and after modification of the membranes with 0.1, 0.5, 1 or 2 mM of n-decylamine (FIG. 9A) or n-dodecylamine (FIG. 9A) (testing conditions: 5 ppm boron, 15,000 ppm NaCl, pressure 40 bar).
FIGs. 10A and 10B present bar graphs showing salt passage of membranes of an SW30-2450 element before (pristine) and after modification of the membranes with 0.1, 0.5, 1 or 2 mM of n-decylamine (FIG. 10A) or n-dodecylamine (FIG. 10B) (testing conditions: 5 ppm boron, 15,000 ppm NaCl, pressure 40 bar).
FIG. 11 presents an ATR-FTIR (attenuated total reflectance Fourier transform infra-red) spectrum of a polyamide membrane (SW30) modified by sorption of decylamine or dodecylamine (modification conditions: pressure 10 bar, alkylamine concentration increased from 0.1 to 2 mM, thereafter the element was autopsied). FIGs. 12A and 12B scanning electron microscopy images of a polyamide membrane (SW30) surface modified by sorption of decylamine (FIG. 12A) or dodecylamine (FIG. 12B) (modification conditions: pressure 10 bar, alkylamine concentration increased from 0.1 to 2 mM, thereafter the element was autopsied; scale bar in FIG. 12A is 200 nm).
FIG. 13 presents a graph showing the boron passage and water permeability (Lp) for pristine commercial seawater reverse osmosis (SWRO) membranes and SWRO membranes modified by sorption of amylamine (C5), octylamine (C8), decylamine (CIO) or dodecylamine (C12); solid symbols represent pristine membranes and open symbols represent modified membranes in conditions producing the most beneficial shift in performance (testing conditions: 5 ppm boron, 15,000 ppm NaCl, pressure 40 bar; except for SWRO data points (> ) which are for 5 ppm boron, 35,000 ppm NaCl, pressure 55 bar)
FIGs. 14A and 14B present graphs showing salt passage, boron passage and water permeability (Lp) of membranes of a brackish water reverse osmosis (BWRO) membrane (BW30) before (pristine) and after exposure to pH 11 for 24 hours resulting in hydrolytic degradation of the membrane, and after modification of the degraded membrane by 1 mM decylamine subsequently to hydrolysis, using carbodiimide-based coupling (FIG. 14A) or by sorption (FIG. 14B) (testing conditions: 5 ppm boron, 1,500 ppm NaCl, pressure 20 bar).
FIGs. 15A and 15B present graphs showing salt passage, boron passage and water permeability (Lp) of membranes of a brackish water reverse osmosis (BWRO) membrane (BW30) before (pristine) and after hydrolysis treatment at pH 11 for 24 hours (pH = 11), and after modification by 1 mM decylamine subsequently to hydrolysis, using carbodiimide-based coupling (FIG. 15A) or by sorption (FIG. 15B) (testing conditions: 5 ppm boron, 1,500 ppm NaCl, pressure 20 bar).
DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION
The present invention, in some embodiments thereof, relates to membranes for reverse osmosis, and more particularly, but not exclusively, to membranes for removing boron from water. Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not necessarily limited in its application to the details of construction and the arrangement of the components and/or methods set forth in the following description and/or illustrated in the drawings and/or the Examples. The invention is capable of other embodiments or of being practiced or carried out in various ways.
While seeking to develop improved membranes useful for reverse osmosis (RO), the present inventors have envisioned that modification of polyamide membranes with immobilized small molecules may reduce pore size and affect pore hydrophobicity in a manner which advantageously enhances rejection of boron, without having a considerable effect on the bulk polyamide properties.
While reducing the present invention to practice, it was uncovered that attachment of linear and/or near-linear alkylamines to the polyamide via non-covalent interactions or amide bond formation results in a considerable enhancement of the ability of membranes to remove boron, without an excessive reduction in water permeability.
According to an aspect of some embodiments of the invention, there is provided a water permeable composite membrane comprising a thin film layer on a porous substrate (as described in detail herein). The thin film layer comprises a polymer and an amine-containing compound associated with the polymer (as described in detail herein), the amine-containing compound comprising at least one aliphatic hydrocarbon moiety attached to an amine group (as described in detail herein).
Herein, the phrase "composite membrane" encompasses any membrane comprising a thin film layer on a porous substrate (according to any of the respective embodiments described herein), and the term "composite" is not intended to be further limiting.
Amine-containing compound:
An amine-containing comprising at least one aliphatic hydrocarbon moiety attached to an amine group according to any of the respective embodiments described herein may be in accordance with any of the embodiments described in this section.
Herein, the term "hydrocarbon" describes an organic moiety that includes, as its basic skeleton, a chain of carbon atoms, substituted mainly by hydrogen atoms. The hydrocarbon can be saturated or non-saturated, comprise aliphatic, alicyclic and/or aromatic moieties, and can optionally be substituted by one or more substituents (other than hydrogen). The hydrocarbon moiety is optionally interrupted by one or more heteroatoms, including, without limitation, one or more oxygen, nitrogen and/or sulfur atoms.
Herein, the term "aliphatic hydrocarbon moiety" describes a hydrocarbon moiety as defined herein which comprises aliphatic and/or alicyclic moieties, and which is devoid of an aromatic moiety.
As exemplified herein, an aromatic hydrocarbon moiety may result in poor membrane performance.
In preferred embodiments of some embodiments of the invention, the aliphatic hydrocarbon moiety described herein is not interrupted by any heteroatoms, although it is optionally substituted by one or more substituents comprising heteroatoms.
Herein, the terms "amine" and "amino" each refer to either a - R'R" group or a -N+R'R"R"' group, wherein R', R" and R' " are each hydrogen or a saturated or unsaturated hydrocarbon moiety (as defined herein), the hydrocarbon moiety being substituted or non-substituted. Optionally, R', R" and R'" are hydrogen or alkyl comprising 1 to 4 carbon atoms. Optionally, R' and R" (and R'", if present) are hydrogen. When substituted, the carbon atom of an R', R" or R'" hydrocarbon moiety which is bound to the nitrogen atom of the amine is preferably not substituted by oxo, such that R', R" and R' " are not (for example) carbonyl, C-carboxy or amide, as these groups are defined herein, except where indicated otherwise.
In some embodiments of any of the embodiments described herein, the amine - containing compound associated with the polymer has the general formula:
Figure imgf000016_0001
wherein:
Ri is an aliphatic hydrocarbon moiety according to any of the respective embodiments described herein; and
R2 and R3 are each independently hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, or a heteroalicyclic, or, alternatively, one or both of R2 and R3 is independently a covalent bond linking the amine-containing compound to the polymer of the thin film or a group participating in a covalent bond linking the amine-containing compound to the polymer of the thin film.
In some embodiments of any of the embodiments described herein, the amine - containing compound (according to any of the respective embodiments described herein) is associated with the polymer via one or more non-covalent interactions. Non-limiting examples of such non-covalent interactions include an ionic interaction and/or hydrogen bond between an amine group of the amine-containing compound (optionally in a positively charged form, e.g., a protonated form) and a group in the polymer (optionally a negatively charged group, e.g., a deprotonated carboxylic acid group), and a hydrophobic interaction, optionally between an aliphatic hydrocarbon moiety of the amine-containing compound and a suitably hydrophobic moiety (e.g., phenyl) of the polymer.
In some embodiments of any of the embodiments described herein, the amine- containing compound has the general formula depicted herein, wherein R2 and R3 are each independently hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, or a heteroalicyclic. Such a compound may optionally be associated with the polymer via non-covalent interactions. In some of the aforementioned embodiments, at least one of R2 and R3 is hydrogen. In some of the aforementioned embodiments, R2 and R3 are each hydrogen.
In some embodiments of any of the embodiments described herein, the amine- containing compound (according to any of the respective embodiments described herein) is associated with the polymer via one or more (e.g., one or two) covalent bonds. In some such embodiments, the covalent bond links an amine group of the amine- containing compound to the polymer.
In some embodiments of any of the embodiments described herein, the amine- containing compound has the general formula depicted herein, wherein at least one of R2 and R3 (optionally only R3) is a covalent bond linking the amine-containing compound to the polymer. In embodiments wherein at least R3 is a covalent bond linking the amine-containing compound to the polymer, the amine-containing compound (in association with the polymer) is in a form of a moiety (e.g., univalent or divalent moiety) having the general formula:
Figure imgf000018_0001
wherein:
Ri is an aliphatic hydrocarbon moiety according to any of the respective embodiments described herein; and
R2 is hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, or a heteroalicyclic (according to any of the respective embodiments described herein), or, alternatively, R2 is a covalent bond linking the amine-containing compound to the polymer or a group participating in a covalent bond linking the amine-containing compound to the polymer (according to any of the respective embodiments described herein),
and the moiety is optionally linked to the polymer via a covalent bond represented herein by the variable R3.
In some embodiments, R2 is hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, or a heteroalicyclic (according to any of the respective embodiments described herein), and the amine-containing compound is linked to the polymer by only one covalent bond (according to any of the respective embodiments described herein). In some such embodiments, R2 is hydrogen.
In some embodiments, R2 and R3 are each a covalent bond linking the amine- containing compound to the polymer (according to any of the respective embodiments described herein), and the amine-containing compound (in association with the polymer) is in a form of a moiety (e.g., divalent moiety) having the general formula:
Figure imgf000018_0002
wherein:
Ri is an aliphatic hydrocarbon moiety according to any of the respective embodiments described herein, and the moiety is optionally linked to the polymer via one covalent bond represented herein by the variable R2 and via another covalent bond represented herein by the variable R3 (optionally groups in the polymer).
In some embodiments of any of the embodiments described herein relating to a covalent bond linking the amine-containing compound to the polymer, the covalent bond is an amide bond (e.g., R2 and/or R3 is a covalent amide bond). In some embodiments, such an amide bond is derived from a carboxylic group or acyl halide group in the polymer.
Herein, the phrase "amide bond" refers to a covalent bond between a -C(=0)- group and a nitrogen atom (optionally a nitrogen atom depicted in a general formula described herein).
In some embodiments of any of the respective embodiments described herein, the -C(=0)- group which participates in the amide bond is further attached to a carbon atom (e.g., wherein the aforementioned -C(=0)- group and carbon atom are part of a polymer described herein, such as a polyamide).
A group participating in a covalent bond linking the amine-containing compound to the polymer (according to any of the respective embodiments described herein) may optionally participate in one such covalent bond or in more than one such covalent bond (e.g., 2 or 3 covalent bonds).
In some embodiments of any of the respective embodiments described herein, a group participating in a covalent bond linking the amine-containing compound to the polymer (according to any of the respective embodiments described herein) is a hydrocarbon (as defined herein), which is optionally substituted or unsubstituted, and saturated or unsaturated. In some embodiments, the group is devoid of an aromatic moiety. In some embodiments, the hydrocarbon is a saturated hydrocarbon.
In some embodiments of any of the respective embodiments described herein, a group participating in a covalent bond linking the amine-containing compound to the polymer (according to any of the respective embodiments described herein) is from 1 to 10 atoms in length (i.e., the nitrogen atom of an amine group of the amine-containing compound is separated from the polymer by no more than 10 atoms). In some embodiments, the group is from 1 to 4 atoms in length. In some embodiments, the group is 1 or 2 atoms in length. In some such embodiments, the group is a hydrocarbon having a length according to any of the aforementioned embodiments.
In some embodiments of any of the respective embodiments described herein, a group participating in a covalent bond linking the amine-containing compound to the polymer (according to any of the respective embodiments described herein) is a hydrocarbon substituted by oxo at a carbon atom attached directly to the nitrogen atom of an amine group of the amine-containing compound (e.g., as depicted in a general formula herein) such that the hydrocarbon is attached to the nitrogen atom via an amide bond.
In some embodiments of any of the respective embodiments described herein, a group participating in a covalent bond linking the amine-containing compound to the polymer comprises a functional group which forms a covalent bond with the polymer, and optionally more than one functional group which forms a covalent bond with the polymer. In some embodiment, the functional group(s) is attached to a hydrocarbon according to any of the respective embodiments described herein (e.g., as a substituent of a hydrocarbon). In some embodiments, the group participating in a covalent bond linking the amine-containing compound consists essentially of the aforementioned functional group(s) being attached to a (substituted or unsubstituted) hydrocarbon according to any of the respective embodiments described herein.
For example, in some embodiments, the functional group comprises a nitrogen atom (e.g., of an amine group, which optionally comprises a hydrocarbon described herein attached to the nitrogen atom) or oxygen atom (e.g., of an alkoxy group comprising the oxygen atom, optionally consisting of the oxygen atom and a hydrocarbon described herein) which is attached via the covalent bond (e.g., an amide or ester bond) to a -C(=0)- group in the polymer, which is optionally derived from a carboxylic acid group or acyl halide group in the polymer.
Additionally or alternatively, in some embodiments, the functional group comprises (and optionally consists of) a -C(=0)- group which is attached via the covalent bond (e.g., an amide or ester bond) to a nitrogen or oxygen atom in the polymer, which is optionally derived from an amine group or hydroxyl group in the polymer. In some embodiments of any of the respective embodiments described herein, at least a portion of (and optionally each of) the groups participating in a covalent bond linking the amine-containing compound to the polymer (according to any of the respective embodiments described herein) are derived from an additional compound linked to the polymer (e.g., the group represents at least a portion of a residue of the additional compound linked to the polymer). Such an additional compound may optionally be reacted with an amine-containing compound to form an amine-containing compound comprising the aforementioned group, followed by formation of a covalent bond between the group and the polymer (e.g., the amine-containing compound comprising the aforementioned group is generated in a form of a molecule prior to being attached to the polymer), and/or the additional compound may optionally be reacted with the polymer to form a polymer attached to a residue of the additional compound, followed by formation of a covalent bond between the residue and the amine-containing compound (e.g., the amine-containing compound comprising the aforementioned group is generated in a form of a moiety attached to the polymer, and not in a form of a free molecule).
In some embodiments of any of the embodiments described herein, a LogP of the amine-containing compound (in a form of an isolated compound, as opposed, for example, to a moiety attached to the polymer) is at least 0.2. In some embodiments, the LogP of the amine-containing compound is at least 0.5. In some embodiments, the LogP is at least 1.0. In some embodiments, the LogP is at least 1.5. In some embodiments, the LogP is at least 2.0. In some embodiments, the LogP is at least 2.5. In some embodiments, the LogP is at least 3.0. In some embodiments, the LogP is at least 3.5. In some embodiments, the LogP is at least 4.0. In some embodiments, the LogP is at least 4.5. In some embodiments, the LogP is at least 5.0.
In some embodiments of any of the embodiments described herein, a LogP of the amine-containing compound (in a form of an isolated compound, as opposed, for example, to a moiety attached to the polymer) is no more than 7.0. In some such embodiments, the LogP is in a range of from 0.2 to 7.0. In some embodiments, the LogP is in a range of from 0.5 to 7.0. In some embodiments, the LogP is in a range of from 1.0 to 7.0. In some embodiments, the LogP is in a range of from 1.5 to 7.0. In some embodiments, the LogP is in a range of from 2.0 to 7.0. In some embodiments, the LogP is in a range of from 2.5 to 7.0. In some embodiments, the LogP is in a range of from 3.0 to 7.0. In some embodiments, the LogP is in a range of from 3.5 to 7.0. In some embodiments, the LogP is in a range of from 4.0 to 7.0. In some embodiments, the LogP is in a range of from 4.5 to 7.0. In some embodiments, the LogP is in a range of from 5.0 to 7.0.
In some embodiments of any of the embodiments described herein, a LogP of the amine-containing compound (in a form of an isolated compound, as opposed, for example, to a moiety attached to the polymer) is no more than 6.0. In some such embodiments, the LogP is in a range of from 0.2 to 6.0. In some embodiments, the LogP is in a range of from 0.5 to 6.0. In some embodiments, the LogP is in a range of from 1.0 to 6.0. In some embodiments, the LogP is in a range of from 1.5 to 6.0. In some embodiments, the LogP is in a range of from 2.0 to 6.0. In some embodiments, the LogP is in a range of from 2.5 to 6.0. In some embodiments, the LogP is in a range of from 3.0 to 6.0. In some embodiments, the LogP is in a range of from 3.5 to 6.0. In some embodiments, the LogP is in a range of from 4.0 to 6.0. In some embodiments, the LogP is in a range of from 4.5 to 6.0. In some embodiments, the LogP is in a range of from 5.0 to 6.0.
In some embodiments of any of the embodiments described herein, a LogP of the amine-containing compound (in a form of an isolated compound, as opposed, for example, to a moiety attached to the polymer) is no more than 5.5. In some such embodiments, the LogP is in a range of from 0.2 to 5.5. In some embodiments, the LogP is in a range of from 0.5 to 5.5. In some embodiments, the LogP is in a range of from 1.0 to 5.5. In some embodiments, the LogP is in a range of from 1.5 to 5.5. In some embodiments, the LogP is in a range of from 2.0 to 5.5. In some embodiments, the LogP is in a range of from 2.5 to 5.5. In some embodiments, the LogP is in a range of from 3.0 to 5.5. In some embodiments, the LogP is in a range of from 3.5 to 5.5. In some embodiments, the LogP is in a range of from 4.0 to 5.5. In some embodiments, the LogP is in a range of from 4.5 to 5.5.
In some embodiments of any of the embodiments described herein, a LogP of the amine-containing compound (in a form of an isolated compound, as opposed, for example, to a moiety attached to the polymer) is no more than 5.0. In some such embodiments, the LogP is in a range of from 0.2 to 5.0. In some embodiments, the LogP is in a range of from 0.5 to 5.0. In some embodiments, the LogP is in a range of from 1.0 to 5.0. In some embodiments, the LogP is in a range of from 1.5 to 5.0. In some embodiments, the LogP is in a range of from 2.0 to 5.0. In some embodiments, the LogP is in a range of from 2.5 to 5.0. In some embodiments, the LogP is in a range of from 3.0 to 5.0. In some embodiments, the LogP is in a range of from 3.5 to 5.0. In some embodiments, the LogP is in a range of from 4.0 to 5.0.
As used herein and in the art, the term "LogP" refers to the base- 10 logarithm of an octanol-water partition coefficient of a compound (i.e., the logarithm of the ratio of the concentration of the compound in octanol to the concentration of the compound in water, when the compound is dissolved in an octanol-water system). The compound is in a neutrally charged form in non-ionized water, and the LogP is determined at a pH at which the compound exists substantially as the neutrally charged form.
Thus, a positive value for a LogP (e.g., as described herein) indicates better solubility in octanol than in water, which may be considered as a sign of hydrophobicity. Hydrophobicity (e.g., LogP) of the amine-containing compound may optionally be enhanced by a suitably hydrophobic aliphatic hydrocarbon moiety (e.g., according to any of the respective embodiments described herein).
Unless indicated otherwise, the term "LogP" refers to experimentally determined values.
In alternative embodiments, a LogP of the amine-containing compound is calculated according to any suitable technique used in the art, for example, calculated based on the method described by Viswanadhan et al. [ Chem Inf Comput Sci 1989, 29:163-172] (e.g., LogP values available at the chemicalize(dot)org website) and/or as described in Bram et al. [Biochem Pharmacol (2007) 74:41-53], and the calculated LogP value is a value according to any of the embodiments described herein regarding LogP values. The contents of Viswanadhan et al. [ Chem Inf Comput Sci 1989, 29: 163-172] and Bram et al. [Biochem Pharmacol (2007) 74:41-53] are incorporated by reference, especially contents therein regarding calculation of octanol-water partition and/or logP values.
In some embodiments of any of the embodiments described herein, a minimum projection area of the amine-containing compound (in a form of an isolated compound, as opposed, for example, to a moiety attached to the polymer) is no more than 31 A2. In some such embodiments, the minimum projection area of the amine-containing compound is no more than 30.5 A2. In some embodiments, the minimum projection area is no more than 30 A2. In some embodiments, the minimum projection area is no more than 29.5 A2. In some embodiments, the minimum projection area is no more than 29 A2. In some embodiments, the minimum projection area is no more than 28.5 A2. In some embodiments, the minimum projection area is no more than 28 A2. In some embodiments, the minimum projection area is no more than 27.5 A2. In some embodiments, the minimum projection area is no more than 27 A2.
In some embodiments of any of the embodiments described herein, a minimum projection area of the amine-containing compound (in a form of an isolated compound, as opposed, for example, to a moiety attached to the polymer) is at least 18 A2. In some such embodiments, the minimum projection area of the amine-containing compound is in a range of from 18 to 31 A2. In some embodiments, the minimum projection area is in a range of from 18 to 30.5 A2. In some embodiments, the minimum projection area is in a range of from 18 to 30 A2. In some embodiments, the minimum projection area is in a range of from 18 to 29.5 A2. In some embodiments, the minimum projection area is in a range of from 18 to 29 A2. In some embodiments, the minimum projection area is in a range of from 18 to 28.5 A2. In some embodiments, the minimum projection area is in a range of from 18 to 28 A2. In some embodiments, the minimum projection area is in a range of from 18 to 27.5 A2. In some embodiments, the minimum projection area is in a range of from 18 to 27 A2.
In some embodiments of any of the embodiments described herein, a minimum projection area of the amine-containing compound (in a form of an isolated compound, as opposed, for example, to a moiety attached to the polymer) is at least 19 A2. In some such embodiments, the minimum projection area of the amine-containing compound is in a range of from 19 to 31 A2. In some embodiments, the minimum projection area is in a range of from 19 to 30.5 A2. In some embodiments, the minimum projection area is in a range of from 19 to 30 A2. In some embodiments, the minimum projection area is in a range of from 19 to 29.5 A2. In some embodiments, the minimum projection area is in a range of from 19 to 29 A2. In some embodiments, the minimum projection area is in a range of from 19 to 28.5 A2. In some embodiments, the minimum projection area is in a range of from 19 to 28 A2. In some embodiments, the minimum projection area is in a range of from 19 to 27.5 A2. In some embodiments, the minimum projection area is in a range of from 19 to 27 A2.
In some embodiments of any of the embodiments described herein, a minimum projection area of the amine-containing compound (in a form of an isolated compound, as opposed, for example, to a moiety attached to the polymer) is at least 20 A2. In some such embodiments, the minimum projection area of the amine-containing compound is in a range of from 20 to 31 A2. In some embodiments, the minimum projection area is in a range of from 20 to 30.5 A2. In some embodiments, the minimum projection area is in a range of from 20 to 30 A2. In some embodiments, the minimum projection area is in a range of from 20 to 29.5 A2. In some embodiments, the minimum projection area is in a range of from 20 to 29 A2. In some embodiments, the minimum projection area is in a range of from 20 to 28.5 A2. In some embodiments, the minimum projection area is in a range of from 20 to 28 A2. In some embodiments, the minimum projection area is in a range of from 20 to 27.5 A2. In some embodiments, the minimum projection area is in a range of from 20 to 27 A2.
In some embodiments of any of the embodiments described herein, a minimum projection area of the amine-containing compound (in a form of an isolated compound, as opposed, for example, to a moiety attached to the polymer) is at least 21 A2. In some such embodiments, the minimum projection area of the amine-containing compound is in a range of from 21 to 31 A2. In some embodiments, the minimum projection area is in a range of from 21 to 30.5 A2. In some embodiments, the minimum projection area is in a range of from 21 to 30 A2. In some embodiments, the minimum projection area is in a range of from 21 to 29.5 A2. In some embodiments, the minimum projection area is in a range of from 21 to 29 A2. In some embodiments, the minimum projection area is in a range of from 21 to 28.5 A2. In some embodiments, the minimum projection area is in a range of from 21 to 28 A2. In some embodiments, the minimum projection area is in a range of from 21 to 27.5 A2. In some embodiments, the minimum projection area is in a range of from 21 to 27 A2.
In some embodiments of any of the embodiments described herein, a minimum projection area of the amine-containing compound (in a form of an isolated compound, as opposed, for example, to a moiety attached to the polymer) is at least 22 A2. In some such embodiments, the minimum projection area of the amine-containing compound is in a range of from 22 to 31 A2. In some embodiments, the minimum projection area is in a range of from 22 to 30.5 A2. In some embodiments, the minimum projection area is in a range of from 22 to 30 A2. In some embodiments, the minimum projection area is in a range of from 22 to 29.5 A2. In some embodiments, the minimum projection area is in a range of from 22 to 29 A2. In some embodiments, the minimum projection area is in a range of from 22 to 28.5 A2. In some embodiments, the minimum projection area is in a range of from 22 to 28 A2. In some embodiments, the minimum projection area is in a range of from 22 to 27.5 A2. In some embodiments, the minimum projection area is in a range of from 22 to 27 A2.
In some embodiments of any of the embodiments described herein, a minimum projection area of the amine-containing compound (in a form of an isolated compound, as opposed, for example, to a moiety attached to the polymer) is at least 23 A2. In some such embodiments, the minimum projection area of the amine-containing compound is in a range of from 23 to 31 A2. In some embodiments, the minimum projection area is in a range of from 23 to 30.5 A2. In some embodiments, the minimum projection area is in a range of from 23 to 30 A2. In some embodiments, the minimum projection area is in a range of from 23 to 29.5 A2. In some embodiments, the minimum projection area is in a range of from 23 to 29 A2. In some embodiments, the minimum projection area is in a range of from 23 to 28.5 A2. In some embodiments, the minimum projection area is in a range of from 23 to 28 A2. In some embodiments, the minimum projection area is in a range of from 23 to 27.5 A2. In some embodiments, the minimum projection area is in a range of from 23 to 27 A2.
In some embodiments of any of the embodiments described herein, a minimum projection area of the amine-containing compound (in a form of an isolated compound, as opposed, for example, to a moiety attached to the polymer) is at least 24 A2. In some such embodiments, the minimum projection area of the amine-containing compound is in a range of from 24 to 31 A2. In some embodiments, the minimum projection area is in a range of from 24 to 30.5 A2. In some embodiments, the minimum projection area is in a range of from 24 to 30 A2. In some embodiments, the minimum projection area is in a range of from 24 to 29.5 A2. In some embodiments, the minimum projection area is in a range of from 24 to 29 A2. In some embodiments, the minimum projection area is in a range of from 24 to 28.5 A2. In some embodiments, the minimum projection area is in a range of from 24 to 28 A2. In some embodiments, the minimum projection area is in a range of from 24 to 27.5 A2. In some embodiments, the minimum projection area is in a range of from 24 to 27 A2.
In some embodiments of any of the embodiments described herein, a minimum projection area of the amine-containing compound (in a form of an isolated compound, as opposed, for example, to a moiety attached to the polymer) is at least 25 A2. In some such embodiments, the minimum projection area of the amine-containing compound is in a range of from 25 to 31 A2. In some embodiments, the minimum projection area is in a range of from 25 to 30.5 A2. In some embodiments, the minimum projection area is in a range of from 25 to 30 A2. In some embodiments, the minimum projection area is in a range of from 25 to 29.5 A2. In some embodiments, the minimum projection area is in a range of from 25 to 29 A2. In some embodiments, the minimum projection area is in a range of from 25 to 28.5 A2. In some embodiments, the minimum projection area is in a range of from 25 to 28 A2. In some embodiments, the minimum projection area is in a range of from 25 to 27.5 A2. In some embodiments, the minimum projection area is in a range of from 25 to 27 A2.
In some embodiments of any of the embodiments described herein, a minimum projection area of the amine-containing compound (in a form of an isolated compound, as opposed, for example, to a moiety attached to the polymer) is at least 22 A2. In some such embodiments, the minimum projection area of the amine-containing compound is in a range of from 26 to 31 A2. In some embodiments, the minimum projection area is in a range of from 26 to 30.5 A2. In some embodiments, the minimum projection area is in a range of from 26 to 30 A2. In some embodiments, the minimum projection area is in a range of from 26 to 29.5 A2. In some embodiments, the minimum projection area is in a range of from 26 to 29 A2. In some embodiments, the minimum projection area is in a range of from 26 to 28.5 A2. In some embodiments, the minimum projection area is in a range of from 26 to 28 A2. In some embodiments, the minimum projection area is in a range of from 26 to 27.5 A2. In some embodiments, the minimum projection area is in a range of from 26 to 27 A2.
Herein and in the art, the phrase "minimum projection area" and its acronym
"MPA" refer to the two-dimensional area of a molecule's three-dimensional van der Waals volume (wherein atoms are represented as spheres whose radius is the van der Waals radius) projected on a plane, wherein the molecule is oriented in such a way that the projected area has the minimal possible value (as compared with other possible orientations of the molecule).
MPA values may optionally be obtained using any appropriate software, e.g., such as available at the chemicalize(dot)org website.
Aliphatic hydrocarbon moiety:
An aliphatic hydrocarbon moiety (as defined herein) according to any of the respective embodiments described herein (including, without limitation, an Ri moiety described herein) may be in accordance with any of the embodiments described in this section.
The aliphatic hydrocarbon moiety according to any of the embodiments describe herein may optionally have any size, and be saturated or unsaturated, and substituted or unsubstituted.
In some embodiments of any of the embodiments described herein, the aliphatic hydrocarbon moiety (according to any of the respective embodiments described herein) contains at least 3 carbon atoms. In some embodiments, the aliphatic hydrocarbon moiety contains at least 4 carbon atoms. In some embodiments, the aliphatic hydrocarbon moiety contains at least 5 carbon atoms. In some embodiments, the aliphatic hydrocarbon moiety contains at least 6 carbon atoms. In some embodiments, the aliphatic hydrocarbon moiety contains at least 7 carbon atoms. In some embodiments, the aliphatic hydrocarbon moiety contains at least 8 carbon atoms. In some embodiments, the aliphatic hydrocarbon moiety contains at least 9 carbon atoms. In some embodiments, the aliphatic hydrocarbon moiety contains at least 10 carbon atoms. In some embodiments, the aliphatic hydrocarbon moiety contains at least 11 carbon atoms. In some embodiments, the aliphatic hydrocarbon moiety contains at least 12 carbon atoms. In some embodiments, the aliphatic hydrocarbon moiety contains at least 13 carbon atoms. In some embodiments, the aliphatic hydrocarbon moiety contains at least 14 carbon atoms. In some embodiments, the aliphatic hydrocarbon moiety contains at least 15 carbon atoms.
In some embodiments of any of the embodiments described herein, the aliphatic hydrocarbon moiety is of from 1 to 30 carbon atoms in length. In some embodiments of any of the embodiments described herein, the aliphatic hydrocarbon moiety (according to any of the respective embodiments described herein) is at least 3 carbon atoms in length. In some embodiments, the aliphatic hydrocarbon moiety is at least 4 carbon atoms in length. In some embodiments, the aliphatic hydrocarbon moiety is at least 5 carbon atoms in length. In some embodiments, the aliphatic hydrocarbon moiety is at least 6 carbon atoms in length. In some embodiments, the aliphatic hydrocarbon moiety is at least 7 carbon atoms in length. In some embodiments, the aliphatic hydrocarbon moiety is at least 8 carbon atoms in length. In some embodiments, the aliphatic hydrocarbon moiety is at least 9 carbon atoms in length. In some embodiments, the aliphatic hydrocarbon moiety is at least 10 carbon atoms in length. In some embodiments, the aliphatic hydrocarbon moiety is at least 11 carbon atoms in length. In some embodiments, the aliphatic hydrocarbon moiety is at least 12 carbon atoms in length. In some embodiments, the aliphatic hydrocarbon moiety is at least 13 carbon atoms in length.
In some embodiments, the aliphatic hydrocarbon moiety is at least 14 carbon atoms in length. In some embodiments, the aliphatic hydrocarbon moiety is at least 15 carbon atoms in length.
As used herein, a "length" of an aliphatic hydrocarbon moiety refers to the number of carbon atoms in a linear chain, wherein the carbon atom at one terminus of the linear chain is closest (among all the atoms in the linear chain) to the amine group according to any of the respective embodiments described herein (and optionally attached to a nitrogen atom of the amine group), and the other atoms in the linear chain are progressively farther from the amine group, such that the other terminus of the linear chain is represented by the carbon atom farthest from the amine group. When two or more linear chains are present in an aliphatic hydrocarbon moiety (e.g., in a branched aliphatic hydrocarbon moiety), the linear chain with the greatest length (as defined herein) is regarded as the length of the aliphatic hydrocarbon moiety. However, when a carbon atom is linked to the amine group via two or more linear chains (e.g., in an aliphatic hydrocarbon moiety which forms and/or comprises a cyclic moiety), the shortest of the two or more linear chains (i.e., having the lowest length as defined herein) represents the distance of said carbon atom from the amine group, and is to be regarded as the length of the aliphatic hydrocarbon moiety (unless there exists a linear chain terminating at a different carbon atom which has a greater length).
In some embodiments of any of the embodiments described herein relating to an amine-containing compound which associates with the polymer via non-covalent interactions, the aliphatic hydrocarbon moiety (according to any of the respective embodiments described herein) contains at least 5 carbon atoms. In some such embodiments, the aliphatic hydrocarbon moiety contains at least 6 carbon atoms. In some such embodiments, the aliphatic hydrocarbon moiety contains at least 7 carbon atoms. In some such embodiments, the aliphatic hydrocarbon moiety contains at least 8 carbon atoms. In some such embodiments, the aliphatic hydrocarbon moiety contains at least 9 carbon atoms. In some such embodiments, the aliphatic hydrocarbon moiety contains at least 10 carbon atoms. In some such embodiments, the aliphatic hydrocarbon moiety contains at least 11 carbon atoms. In some such embodiments, the aliphatic hydrocarbon moiety contains at least 12 carbon atoms. In some such embodiments, the aliphatic hydrocarbon moiety contains at least 13 carbon atoms. In some such embodiments, the aliphatic hydrocarbon moiety contains at least 14 carbon atoms. In some such embodiments, the aliphatic hydrocarbon moiety contains at least 15 carbon atoms.
In some embodiments of any of the embodiments described herein relating to an amine-containing compound which associates with the polymer via non-covalent interactions, the aliphatic hydrocarbon moiety (according to any of the respective embodiments described herein) is at least 5 carbon atoms in length. In some such embodiments, the aliphatic hydrocarbon moiety is at least 6 carbon atoms in length. In some such embodiments, the aliphatic hydrocarbon moiety is at least 7 carbon atoms in length. In some such embodiments, the aliphatic hydrocarbon moiety is at least 8 carbon atoms in length. In some such embodiments, the aliphatic hydrocarbon moiety is at least 9 carbon atoms in length. In some such embodiments, the aliphatic hydrocarbon moiety is at least 10 carbon atoms in length. In some such embodiments, the aliphatic hydrocarbon moiety is at least 11 carbon atoms in length. In some such embodiments, the aliphatic hydrocarbon moiety is at least 12 carbon atoms in length.
In some such embodiments, the aliphatic hydrocarbon moiety is at least 13 carbon atoms in length. In some such embodiments, the aliphatic hydrocarbon moiety is at least 14 carbon atoms in length. In some such embodiments, the aliphatic hydrocarbon moiety is at least 15 carbon atoms in length.
Without being bound by any particular theory, it is believed that a larger size (e.g., in terms of length and/or number of carbon atoms) of an aliphatic hydrocarbon moiety in the amine-containing compound (according to any of the respective embodiments described herein) may correlate with the ability of the amine-containing compound to efficiently associate with the polymer via non-covalent interactions.
In some embodiments of any of the embodiments described herein, the aliphatic hydrocarbon moiety according to any of the respective embodiments described herein consists of a linear aliphatic hydrocarbon moiety which is unsubstituted or is substituted by one or more substituents which may be, for example, alkyl, alkenyl, alkynyl, cycloalkyl, heteroalicyclic, halo, hydroxy, alkoxy, thiohydroxy, thioalkoxy, sulfinyl, sulfonyl, cyano, nitro, azide, phosphonyl, phosphinyl, oxo, carbonyl, thiocarbonyl, urea, thiourea, O-carbamyl, N-carbamyl, O-thiocarbamyl, N-thiocarbamyl, C-amido, NT- amido, C-carboxy, O-carboxy, sulfonamido, and/or amino (as these groups are defined herein). In some embodiments, the substituents of a linear aliphatic hydrocarbon moiety are alkyl, alkenyl, alkynyl, cycloalkyl, or halo.
Herein, the term "linear aliphatic hydrocarbon moiety" describes an aliphatic hydrocarbon moiety as defined herein which does not comprise an alicyclic moiety, except optionally as a substituent of the linear aliphatic hydrocarbon moiety.
In preferred embodiments of any of the embodiments described herein, any substitution of a linear aliphatic hydrocarbon moiety described herein is relatively limited, such that the substitution does not greatly alter the linear character of the moiety structure.
For example, in some embodiments of any of the embodiments described herein, the aliphatic hydrocarbon moiety consists of a linear aliphatic hydrocarbon moiety which is unsubstituted or is substituted by one or more substituents, each substituent being no more than 3 atoms in length. That is, each atom in a substituent is separated from the linear backbone chain of the hydrocarbon moiety by no more than two atoms (e.g., being attached directly to the linear backbone chain, attached to an atom which is attached to the linear backbone chain, and/or attached to an atom which is attached to an atom attached to the linear backbone chain). Examples of such substituents include, without limitation, Ci-2-alkyl (e.g., methyl, ethyl), C2-alkenyl (e.g., vinyl), O-alkynyl (e.g., ethynyl), and cyclopropyl, each being optionally substituted or unsubstituted (e.g., at the 1- and/or 2-position), and halo.
In some embodiments of any of the embodiments described herein, the aliphatic hydrocarbon moiety consists of a linear aliphatic hydrocarbon moiety which is unsubstituted or is substituted by one or more substituents, each substituent being no more than 2 atoms in length. That is, each atom in a substituent is separated from the linear backbone chain of the hydrocarbon moiety by no more than one atom (e.g., being attached directly to the linear backbone chain and/or attached to an atom which is attached to the linear backbone chain). In some of the aforementioned embodiments, each substituent contains no more than one atom which is not a hydrogen atom. Examples of such substituents include, without limitation, substituents which are 2 atoms in length, such as methyl (optionally unsubstituted or substituted by oxo or 1-3 halo substituents), hydroxyl, thiohydroxy and -NH2; and substituents containing only one atom, such as halo and oxo.
In some embodiments of any of the embodiments described herein, the aliphatic hydrocarbon moiety consists of a linear aliphatic hydrocarbon moiety which is unsubstituted or is substituted by no more than three substituents. In some embodiments, the linear aliphatic hydrocarbon moiety is substituted by no more than two substituents. In some embodiments, the linear aliphatic hydrocarbon moiety is substituted by no more than one substituent. In some of the aforementioned embodiments, the aliphatic hydrocarbon moiety consists of an unsubstituted linear aliphatic hydrocarbon moiety.
In some embodiments of any of the embodiments described herein, the aliphatic hydrocarbon moiety consists of a linear aliphatic hydrocarbon moiety which is unsubstituted or is substituted, wherein if substituted the linear aliphatic hydrocarbon moiety comprises no more than one substituent attached to each carbon atom in the linear aliphatic hydrocarbon moiety.
Without being bound by any particular theory, it is believed that two substituents - including small substituents such as methyl - attached to the same atom in a linear backbone may alter the character of a moiety significantly more than do the same substituents when attached to different atoms in the linear backbone. Membrane structure:
As described herein, a composite membrane according to any of the embodiments described herein comprises a thin film on a porous substrate, the thin film layer comprising a polymer and an amine-containing compound associated with the polymer (e.g., according to any of the any of the embodiments described herein relating to an amine-containing compound).
In some embodiments of any of the embodiments described herein, the composite membrane is made from two or more constituent materials with significantly different physical and/or chemical properties (e.g., in accordance with a commonly used definition of a "composite material"), for example, wherein the thin film layer comprises at least one of such materials and the porous layer comprises at least one other such materials.
Herein, a "thin film" or "thin film layer" refers to a layer of a material, preferably a polymeric material (e.g., a material comprising the polymer in the thin film layer according to any of the respective embodiments described herein), which has an average thickness of no more than 5 μιη.
In preferred embodiments, an average thickness of the thin film layer is no more than 2 μηι. In some embodiments of any of the embodiments described herein, an average thickness of the thin film layer is no more than 1 μιη. In some embodiments of any of the embodiments described herein, an average thickness of the thin film layer is no more than 500 nm (0.5 μιη). In some embodiments, an average thickness of the thin film layer is no more than 300 nm. In some embodiments, an average thickness of the thin film layer is no more than 200 nm. In some embodiments, an average thickness of the thin film layer is no more than 150 nm. In some embodiments, an average thickness of the thin film layer is no more than 100 nm.
In some embodiments of any of the embodiments described herein, an average thickness of the thin film layer is at least 15 nm. In some embodiments, an average thickness of the thin film layer is in a range of from 15 nm to 1 μιη. In some embodiments, an average thickness of the thin film layer is in a range of from 15 nm to 500 nm. In some embodiments, an average thickness of the thin film layer is in a range of from 15 nm to 300 nm. In some embodiments, an average thickness of the thin film layer is in a range of from 15 nm to 100 nm. In some embodiments, an average thickness of the thin film layer is in a range of from 15 nm to 50 nm.
In some embodiments of any of the embodiments described herein, an average thickness of the thin film layer is at least 50 nm. In some embodiments, an average thickness of the thin film layer is in a range of from 50 nm to 1 μιη. In some embodiments, an average thickness of the thin film layer is in a range of from 50 nm to 500 nm. In some embodiments, an average thickness of the thin film layer is in a range of from 50 nm to 300 nm.
In some embodiments of any of the embodiments described herein, an average thickness of the thin film layer is at least 100 nm. In some embodiments, an average thickness of the thin film layer is in a range of from 100 nm to 1 μηι. In some embodiments, an average thickness of the thin film layer is in a range of from 100 nm to 500 nm. In some embodiments, an average thickness of the thin film layer is in a range of from 100 nm to 300 nm. In some embodiments, an average thickness of the thin film layer is in a range of from 150 nm to 200 nm.
Herein, a "porous substrate" refers to a substrate which is sufficiently porous (e.g., with respect to a size of pores therein) to allow an aqueous solution (e.g., an aqueous solution of NaCl and boric acid described herein) to pass through the substrate without filtration of solutes on the solution.
In preferred embodiments, a water permeability of the porous substrate (e.g., as determined according to any of the respective embodiments described herein) is greater than a water permeability of the thin film layer, such that the porous substrate does not reduce a water permeability of the composite membrane considerably beyond a degree to which the thin film layer limits water permeability.
In some embodiments of any of the embodiments described herein, the porous substrate comprises a (porous) layer of a polymer, optionally polyethersulfone and/or polysulfone, upon which the thin film layer is deposited. Examples of additional suitable polymers for a porous layer include, without limitation, polyimide, polyamide, polyetherimide, polyacrylonitrile, polymethyl methacrylate, polyolefins (e.g., polyethylene, polypropylene) and halogenated olefins (e.g., polyvinylidene fluoride).
In some embodiments of any of the embodiments described herein, an average thickness of the layer of a polymer (upon which the thin film layer is deposited) is in a range of from 5 to 500 μιη. In some embodiments, the average thickness is in a range of from 10 to 250 μιη. In some embodiments, the average thickness is in a range of from 25 to 100 μηι. In some embodiments, the average thickness is about 50 μιη.
In some embodiments of any of the embodiments described herein, the porous substrate further comprises a (porous) support sheet underlying the layer of a polymer (e.g., the layer of a polymer is between the support sheet and the thin film layer). In some embodiments, the sheet is a fabric sheet, optionally a non-woven fabric. The support sheet preferably enhances a mechanical strength of the composite membrane.
The polymer in the thin film layer according to any of the embodiments described herein may be any individual polymer (homopolymer or copolymer) or mixture of polymers known in the art which are suitable for forming the thin film layer, for example, a thin film layer suitable for reverse osmosis.
Examples of polymers suitable for inclusion in a composite membrane (e.g., for use in reverse osmosis) include, without limitation cellulose acetate and polyamides.
In some embodiments of any of the embodiments described herein, the thin film layer comprises a polyamide.
Herein, the term "polyamide" refers to a polymer comprising repeating units, wherein at least a portion of the repeating units are linked to each other via an amide linking group (i.e., -C(=0)N(R')-, wherein R' is as defined herein, and is optionally hydrogen). The repeating units may optionally be derived from monomers comprising at least one carboxylic group and at least one amine group (which are linked form amide linking groups between units) and/or from monomers comprising at least two carboxylic groups in combination with monomers comprising at least two amine groups.
Examples of repeating units in a polyamide include, without limitation, units derived from a monomer comprising two or more carboxylic acid or acyl halide groups (e.g., units of adipate, succinate, cyclohexane dicarboxylic acid, cyclobutane dicarboxylic acid, cyclohexane tricarboxylic acid, cyclobutane tricarboxylic acid, terephthalate, phthalate, isophthalate, naphthalene dicarboxylic acid, biphenyl dicarboxylic acid, azobenzene dicarboxylic acid and benzene-tricarboxylic acid, or their corresponding acyl halides, each being optionally substituted or unsubstituted), which may optionally be form a polyamide in combination with units derived from a monomer comprising two or more amine groups (e.g., phenylenediamine, diaminotoluene, diaminoanisole, xylylenediamine, diaminobenzoic acid, triaminobenzene, alkylene diamines such as ethylene diamine, propylenediamine, and hexylene diamine, and tris(2- diaminoethyl)amine, each being optionally substituted or unsubstituted); and units of amino acids (compounds comprising at least one amine group and at least one carboxylic acid group) or their respective acyl halides wherein a carboxylic acid group is replaced by an acyl halide group (e.g., aminobenzoic acid, diaminobenzoic acid, each being optionally substituted or unsubstituted), which may optionally form a polyamide with each other.
In some embodiments, the polyamide comprises an aromatic polyamide, wherein at least a portion of the repeating units comprising an aromatic group. Examples of such units include, for example, phenylenediamine (e.g., m-phenylenediamine, p- phenylenediamine), xylylenediamine, triaminobenzene (e.g., 1,3,5-triaminobenzene, 1,3,4-triaminobenzene), diaminobenzoic acid (e.g., 3, 5 -diaminobenzoic acid), diaminotoluene (e.g., 2,4-diaminotoluene), diaminoanisole (e.g., 2,4-diaminoanisole), and terephthalate, phthalate, isophthalate, benzene-tricarboxylic acid (e.g., 1,3,5- benzene-tricarboxylic acid), biphenyl dicarboxylic acid, azobenzene dicarboxylic acid and naphthalene dicarboxylic acid (or their corresponding acyl halides), each being optionally substituted or unsubstituted.
It is expected that during the life of a patent maturing from this application many relevant composite membranes suitable for use in reverse osmosis will be developed and the scope of the terms "composite membrane", "thin film", "porous substrate", "polymer" (in the context of a polymer comprised by a thin film) and "polyamide" are intended to include all such new technologies a priori.
Membrane permeability:
In some embodiments of any of the embodiments described herein, a boron passage rate of the composite membrane is less than 35 %. In some such embodiments, the boron passage rate of the composite membrane is less than 30 %. In some such embodiments, the boron passage rate of the composite membrane is less than 30 %. In some such embodiments, the boron passage rate of the composite membrane is less than 25 %. In some such embodiments, the boron passage rate of the composite membrane is less than 20 %. In some such embodiments, the boron passage rate of the composite membrane is less than 15 %. In some such embodiments, the boron passage rate of the composite membrane is less than 12 %. In some such embodiments, the boron passage rate of the composite membrane is less than 10 %. In some such embodiments, the boron passage rate of the composite membrane is less than 8 %. In some such embodiments, the boron passage rate of the composite membrane is less than 6 %.
In some embodiments of any of the embodiments described herein, a water permeability of the composite membrane is at least 0.2 liters per square meter per bar per hour (l-m"2-baf ^hour"1). In some such embodiments, the water permeability of the composite membrane is at least 0.25 l-m"2-baf ^hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.3 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.35
1- m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.4 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.45 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.5 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.55 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.6 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.65 l-m"
2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.8 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.85 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.9 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 1.0 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 1.25 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 1.5 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 2.0 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 3.0 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 4.0 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 5.0 l-m" 2· bar"1 -hour"1.
Herein, a "boron passage" or "boron passage rate" (these terms being used herein interchangeably) of a membrane refers to the concentration of boric acid (including both undissociated boric acid and borate ion) measured as total B (e.g., by inductively coupled plasma (ICP) analysis) in a permeate (i.e., after a passage of a boric acid-containing feed solution once through the membrane) divided by the concentration of boric acid (including undissociated boric acid and borate ion) measured as total B in the feed solution (i.e., prior to passage of the feed solution through the membrane), the ratio optionally being expressed as a percentage (by multiplying a ratio by 100 %).
Herein, a "water permeability" of a membrane refers to an amount of an aqueous solution (e.g., as measured in liters) which passes through the membrane per unit time, divided by the product of the area of the membrane (optionally 11.3 cm2) and the feed pressure (optionally 55 bar).
Unless explicitly stated otherwise, a boron passage rate and/or water permeability according to any one of the respective embodiments described herein is determined under the following conditions: aqueous solution of boric acid (5ppm) and NaCl (32,000 ppm) at pH 7, and at a feed pressure of 55 bar. The boron passage rate and/or water permeability may optionally be determined using a 150 ml pressurized (e.g., nitrogen-pressurized) dead-end stirred cell having a membrane area of 11.3 cm2, as exemplified herein.
In some embodiments of any of the embodiments described herein, a boron passage rate of the composite membrane is less than 35 %, and a water permeability of the composite membrane is at least 0.2 liters per square meter per bar per hour (l-m" 2-bar"1-hour"1). In some such embodiments, the water permeability of the composite membrane is at least 0.25 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.3 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.35 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.4 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.45 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.5 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.55 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.6 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.65 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.8 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.85 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.9 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 1.0 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 1.25 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 1.5 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 2.0 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 3.0 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 4.0 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 5.0 l-m" 2- bar"1 -hour"1.
In some embodiments of any of the embodiments described herein, a boron passage rate of the composite membrane is less than 30 %, and a water permeability of the composite membrane is at least 0.2 liters per square meter per bar per hour (l-m" 2-bar"1-hour"1). In some such embodiments, the water permeability of the composite membrane is at least 0.25 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.3 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.35 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.4 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.45 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.5 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.55 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.6 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.65 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.8 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.85 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.9 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 1.0 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 1.25 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 1.5 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 2.0 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 3.0 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 4.0 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 5.0 l-m" 2- bar"1 -hour"1.
In some embodiments of any of the embodiments described herein, a boron passage rate of the composite membrane is less than 25 %, and a water permeability of the composite membrane is at least 0.2 liters per square meter per bar per hour (l-m" 2-bar"1-hour"1). In some such embodiments, the water permeability of the composite membrane is at least 0.25 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.3 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.35 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.4 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.45 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.5 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.55 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.6 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.65 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.8 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.85 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.9 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 1.0 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 1.25 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 1.5 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 2.0 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 3.0 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 4.0 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 5.0 l-m" 2- bar"1 -hour"1.
In some embodiments of any of the embodiments described herein, a boron passage rate of the composite membrane is less than 20 %, and a water permeability of the composite membrane is at least 0.2 liters per square meter per bar per hour (l-m" 2-bar"1-hour"1). In some such embodiments, the water permeability of the composite membrane is at least 0.25 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.3 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.35 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.4 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.45 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.5 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.55 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.6 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.65 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.8 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.85 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.9 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 1.0 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 1.25 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 1.5 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 2.0 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 3.0 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 4.0 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 5.0 l-m" 2- bar"1 -hour"1.
In some embodiments of any of the embodiments described herein, a boron passage rate of the composite membrane is less than 15 %, and a water permeability of the composite membrane is at least 0.2 liters per square meter per bar per hour (l-m" 2-bar"1-hour"1). In some such embodiments, the water permeability of the composite membrane is at least 0.25 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.3 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.35 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.4 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.45 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.5 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.55 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.6 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.65 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.8 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.85 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.9 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 1.0 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 1.25 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 1.5 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 2.0 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 3.0 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 4.0 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 5.0 l-m" 2- bar"1 -hour"1.
In some embodiments of any of the embodiments described herein, a boron passage rate of the composite membrane is less than 12 %, and a water permeability of the composite membrane is at least 0.2 liters per square meter per bar per hour (l-m" 2-bar"1-hour"1). In some such embodiments, the water permeability of the composite membrane is at least 0.25 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.3 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.35 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.4 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.45 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.5 l-m" 2· bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.55 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.6 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.65 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m"2- bar"1 -hour"1.
In some such embodiments, the water permeability of the composite membrane is at least 0.8 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.85 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.9 l-m ^bar ^hour"1. In some such embodiments, the water permeability of the composite membrane is at least 1.0 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 1.25 l-m ^bar ^hour"1. In some such embodiments, the water permeability of the composite membrane is at least 1.5 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 2.0
1- m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 3.0 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 4.0 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 5.0 l-m"
2- bar"1 -hour"1.
In some embodiments of any of the embodiments described herein, a boron passage rate of the composite membrane is less than 10 %, and a water permeability of the composite membrane is at least 0.2 liters per square meter per bar per hour (l-m" 2-bar"1-hour"1). In some such embodiments, the water permeability of the composite membrane is at least 0.25 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.3 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.35 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.4 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.45 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.5 l-m" 2· bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.55 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.6 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.65 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m"2- bar"1 -hour"1.
In some such embodiments, the water permeability of the composite membrane is at least 0.8 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.85 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.9 l-m ^bar ^hour"1. In some such embodiments, the water permeability of the composite membrane is at least 1.0 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 1.25 l-m ^bar ^hour"1. In some such embodiments, the water permeability of the composite membrane is at least 1.5 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 2.0
1- m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 3.0 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 4.0 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 5.0 l-m"
2- bar"1 -hour"1.
In some embodiments of any of the embodiments described herein, a boron passage rate of the composite membrane is less than 8 %, and a water permeability of the composite membrane is at least 0.2 liters per square meter per bar per hour (l-m" 2-bar"1-hour"1). In some such embodiments, the water permeability of the composite membrane is at least 0.25 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.3 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.35 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.4 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.45 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.5 l-m" 2· bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.55 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.6 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.65 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m"2- bar"1 -hour"1.
In some such embodiments, the water permeability of the composite membrane is at least 0.8 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.85 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.9 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 1.0 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 1.25 l-m ^bar ^hour"1. In some such embodiments, the water permeability of the composite membrane is at least 1.5 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 2.0
1- m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 3.0 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 4.0 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 5.0 l-m"
2- bar"1 -hour"1.
In some embodiments of any of the embodiments described herein, a boron passage rate of the composite membrane is less than 6 %, and a water permeability of the composite membrane is at least 0.2 liters per square meter per bar per hour (l-m" 2-bar"1-hour"1). In some such embodiments, the water permeability of the composite membrane is at least 0.25 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.3 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.35 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.4 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.45 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.5 l-m" 2· bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.55 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.6 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.65 l-m" 2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.75 l-m"2- bar"1 -hour"1.
In some such embodiments, the water permeability of the composite membrane is at least 0.8 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.85 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 0.9 l-m ^bar ^hour"1. In some such embodiments, the water permeability of the composite membrane is at least 1.0 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 1.25 l-m ^bar ^hour"1. In some such embodiments, the water permeability of the composite membrane is at least 1.5 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 2.0
1- m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 3.0 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 4.0 l-m"2- bar"1 -hour"1. In some such embodiments, the water permeability of the composite membrane is at least 5.0 l-m"
2- bar"1 -hour"1.
In some embodiments of any of the embodiments described herein, a ratio of a boron passage rate of the composite membrane to water permeability of the composite membrane is less than 30 % boron passage rate per 1.0 liter per square meter per bar per hour water permeability (30 % per l-m ^bar ^hour"1). In some such embodiments, the ratio is less than 25 % boron passage rate per 1.0 liter per square meter per bar per hour water permeability (25 % per l-m ^bar ^hour"1). In some such embodiments, the ratio is less than 20 % boron passage rate per 1.0 liter per square meter per bar per hour water permeability (20 % per l-m ^bar ^hour"1). In some such embodiments, the ratio is less than 15 % boron passage rate per 1.0 liter per square meter per bar per hour water permeability (15 % per l-m ^bar ^hour"1). In some such embodiments, the ratio is less than 10 % boron passage rate per 1.0 liter per square meter per bar per hour water permeability (10 % per l-m ^bar ^hour 1).
As a boron passage rate and/or water permeability of a composite membrane according to embodiments of the invention may be affected by the properties of components of the composite membrane other than an amine-containing compound (according to any of the respective embodiments described herein), such as the polymer described herein, an effect of the amine-containing compound (according to any of the respective embodiments described herein) on embodiments of the invention may optionally be characterized by comparing a boron passage rate and/or water permeability of a composite membrane according to embodiments of the invention with the boron passage rate and/or water permeability a corresponding composite membrane without the amine-containing compound covalently and/or non-covalently bound to the polymer.
In some embodiments of any of the embodiments described herein, a boron passage rate of the composite membrane is less than 80 % of a boron passage rate of a corresponding composite membrane without the amine-containing compound covalently and/or non-covalently bound to the polymer (e.g., the boron passage rate is reduced by over 20 % due to the presence of the amine-containing compound). In some such embodiments, a boron passage rate of the composite membrane is less than 70 % of a boron passage rate of the aforementioned corresponding composite membrane without the amine-containing compound. In some such embodiments, a boron passage rate of the composite membrane is less than 60 % of a boron passage rate of the corresponding composite membrane without the amine-containing compound. In some such embodiments, a boron passage rate of the composite membrane is less than 50 % of a boron passage rate of the corresponding composite membrane without the amine - containing compound. In some such embodiments, a boron passage rate of the composite membrane is less than 40 % of a boron passage rate of the corresponding composite membrane without the amine-containing compound. In some such embodiments, a boron passage rate of the composite membrane is less than 30 % of a boron passage rate of the corresponding composite membrane without the amine - containing compound.
In some embodiments of any of the embodiments described herein, a water permeability of the composite membrane is at least 20 % of a water permeability of a corresponding composite membrane without the amine-containing compound covalently and/or non-covalently bound to the polymer (e.g., the water permeability is reduced by no more than 80 % due to the presence of the amine-containing compound). In some such embodiments, a water permeability of the composite membrane is at least 30 % of a water permeability of the aforementioned corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 40 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 50 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 60 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 70 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 80 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 90 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 100 % of a water permeability of the corresponding composite membrane (e.g., the water permeability is not reduced at all, and is optionally increased, due to the presence of the amine-containing compound).
In some embodiments of any of the embodiments described herein, a boron passage rate of the composite membrane is less than 80 % of a boron passage rate of a corresponding composite membrane without the amine-containing compound covalently and/or non-covalently bound to the polymer, and a water permeability of the composite membrane is at least 20 % of a water permeability of the aforementioned corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 30 % of a water permeability of the aforementioned corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 40 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 50 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 60 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 70 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 80 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 90 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 100 % of a water permeability of the corresponding composite membrane (e.g., the water permeability is not reduced at all, and is optionally increased, due to the presence of the amine-containing compound).
In some embodiments of any of the embodiments described herein, a boron passage rate of the composite membrane is less than 70 % of a boron passage rate of a corresponding composite membrane without the amine-containing compound covalently and/or non-covalently bound to the polymer, and a water permeability of the composite membrane is at least 20 % of a water permeability of the aforementioned corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 30 % of a water permeability of the aforementioned corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 40 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 50 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 60 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 70 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 80 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 90 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 100 % of a water permeability of the corresponding composite membrane (e.g., the water permeability is not reduced at all, and is optionally increased, due to the presence of the amine-containing compound).
In some embodiments of any of the embodiments described herein, a boron passage rate of the composite membrane is less than 60 % of a boron passage rate of a corresponding composite membrane without the amine-containing compound covalently and/or non-covalently bound to the polymer, and a water permeability of the composite membrane is at least 20 % of a water permeability of the aforementioned corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 30 % of a water permeability of the aforementioned corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 40 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 50 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 60 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 70 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 80 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 90 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 100 % of a water permeability of the corresponding composite membrane (e.g., the water permeability is not reduced at all, and is optionally increased, due to the presence of the amine-containing compound).
In some embodiments of any of the embodiments described herein, a boron passage rate of the composite membrane is less than 50 % of a boron passage rate of a corresponding composite membrane without the amine-containing compound covalently and/or non-covalently bound to the polymer, and a water permeability of the composite membrane is at least 20 % of a water permeability of the aforementioned corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 30 % of a water permeability of the aforementioned corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 40 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 50 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 60 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 70 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 80 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 90 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 100 % of a water permeability of the corresponding composite membrane (e.g., the water permeability is not reduced at all, and is optionally increased, due to the presence of the amine-containing compound).
In some embodiments of any of the embodiments described herein, a boron passage rate of the composite membrane is less than 40 % of a boron passage rate of a corresponding composite membrane without the amine-containing compound covalently and/or non-covalently bound to the polymer, and a water permeability of the composite membrane is at least 20 % of a water permeability of the aforementioned corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 30 % of a water permeability of the aforementioned corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 40 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 50 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 60 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 70 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 80 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 90 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 100 % of a water permeability of the corresponding composite membrane (e.g., the water permeability is not reduced at all, and is optionally increased, due to the presence of the amine-containing compound).
In some embodiments of any of the embodiments described herein, a boron passage rate of the composite membrane is less than 30 % of a boron passage rate of a corresponding composite membrane without the amine-containing compound covalently and/or non-covalently bound to the polymer, and a water permeability of the composite membrane is at least 20 % of a water permeability of the aforementioned corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 30 % of a water permeability of the aforementioned corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 40 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 50 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 60 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 70 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 80 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 90 % of a water permeability of the corresponding composite membrane. In some such embodiments, a water permeability of the composite membrane is at least 100 % of a water permeability of the corresponding composite membrane (e.g., the water permeability is not reduced at all, and is optionally increased, due to the presence of the amine-containing compound). In some embodiments of any of the embodiments described herein, a ratio of a boron passage rate to water permeability of the composite membrane (e.g., as determined in units of % boron passage rate per liter per square meter per bar per hour water permeability, as described hereinabove) is less than 90 % of a ratio of a boron passage rate to water permeability of a corresponding composite membrane without the amine-containing compound covalently and/or non-covalently bound to the polymer. In some such embodiments, the ratio of boron passage rate to water permeability of the composite membrane is less than 80 % of a ratio of boron passage rate to water permeability of the aforementioned corresponding composite membrane.
In some embodiments, the ratio of boron passage rate to water permeability of the composite membrane is less than 70 % of a ratio of boron passage rate to water permeability of the aforementioned corresponding composite membrane. In some embodiments, the ratio of boron passage rate to water permeability of the composite membrane is less than 60 % of a ratio of boron passage rate to water permeability of the aforementioned corresponding composite membrane. In some embodiments, the ratio of boron passage rate to water permeability of the composite membrane is less than 50 % of a ratio of boron passage rate to water permeability of the aforementioned corresponding composite membrane. In some embodiments, the ratio of boron passage rate to water permeability of the composite membrane is less than 40 % of a ratio of boron passage rate to water permeability of the aforementioned corresponding composite membrane. In some embodiments, the ratio of boron passage rate to water permeability of the composite membrane is less than 30 % of a ratio of boron passage rate to water permeability of the aforementioned corresponding composite membrane.
In some embodiments, the ratio of boron passage rate to water permeability of the composite membrane is less than 20 % of a ratio of boron passage rate to water permeability of the aforementioned corresponding composite membrane.
It is to be understood that a corresponding composite membrane is subjected to the same conditions as the composite membrane (e.g., according to any of the respective embodiments described herein) being compared thereto. For example, in embodiments, wherein a used and/or degraded composite membrane is modified by an amine- containing compound (e.g., according to any of the respective embodiments described herein), the corresponding composite membrane is one which has been used and/or degraded under corresponding conditions.
Preparation of composite membrane:
According to an aspect of some embodiments described herein, there is provided a process for preparing the water permeable composite membrane according to any of the respective embodiments described herein, the process comprising contacting a thin film layer comprising a polymer described herein (according to any of the embodiments described herein relating to a thin film layer and/or polymer) with an amine-containing compound described herein (according to any of the embodiments described herein relating to an amine-containing compound).
The thin film layer comprising a polymer (prior to contact with an amine- containing compound) may optionally be prepared according to any technique known in the art for preparing a thin film layer suitable for a water permeable composite membrane (e.g., a composite membrane suitable for reverse osmosis), and may optionally be obtained from a commercial source.
When contacting a thin film layer with an amine-containing compound, the thin film layer is optionally in a form of a component of a composite membrane comprising the thin film layer on a porous substrate, for example, a composite membrane according to any of the respective embodiments described herein, but without the amine-containing compound therein.
In some embodiments of any of the embodiments described herein relating to a process for preparing the water permeable composite membrane, the process further comprises contacting the thin film layer with an activator of a group in the polymer (e.g., prior to and/or concomitantly with contacting the thin film layer comprising a polymer with an amine-containing compound), the activator being capable of forming a covalent bond between the polymer and the amine-containing compound, for example, by forming a covalent bond between a group in the polymer and an amine group in the amine-containing compound. Any suitable activator known in the art may be used.
In some embodiments of any of the embodiments described herein relating to a process for preparing the water permeable composite membrane, the polymer comprises free carboxylic acid groups, e.g., prior to contacting the thin film layer comprising a polymer with an amine-containing compound (according to any of the respective embodiments described herein). In some such embodiments, the process further comprises contacting the thin film layer with an activator of carboxylic acid groups (e.g., prior to and/or concomitantly with contacting the thin film layer comprising a polymer with an amine-containing compound), the activator being capable of forming a covalent bond between carboxylic acid groups and the amine-containing compound, for example, by forming an amide bond between carboxylic acid groups and amine groups. Examples of suitable amide-bond-forming activators include, without limitation, coupling agents such as carbodiimide agents (e.g., any carbodiimide agent used in the art), which may be used with or without an additional activator such as N-hydroxysuccinimide (which forms an activated ester).
In some embodiments of any of the embodiments described herein, the polymer comprises both free carboxylic groups and amide groups within the polymer (e.g., the polymer comprises a polyamide), and a ratio of free carboxylic acid groups to amide groups in the polymer prior to contacting the thin film layer with an activator of carboxylic acid groups (if the embodiment includes use of an activator) is in a range of from 1:50 to 1: 1 (free carboxylic acid groups:amide groups). In some embodiments, the ratio is in a range of from 1:25 to 1:2. In some embodiments, the ratio is in a range of from 1: 15 to 1:4.
In some embodiments of any of the embodiments described herein, a ratio of free carboxylic acid groups to amide groups in the polymer prior to contacting the thin film layer with an activator of carboxylic acid groups (if the embodiment includes use of an activator) is in a range of from 1:50 to 1:2 (free carboxylic acid groups:amide groups). In some embodiments, the ratio is in a range of from 1:50 to 1:4. In some embodiments, the ratio is in a range of from 1:50 to 1:8. In some embodiments, the ratio is in a range of from 1:50 to 1: 15. In some embodiments, the ratio is in a range of from 1:50 to 1:25.
In some embodiments of any of the embodiments described herein, a ratio of free carboxylic acid groups to amide groups in the polymer prior to contacting the thin film layer with an activator of carboxylic acid groups (if the embodiment includes use of an activator) is in a range of from 1:25 to 1: 1 (free carboxylic acid groups:amide groups). In some embodiments, the ratio is in a range of from 1: 15 to 1: 1. In some embodiments, the ratio is in a range of from 1:8 to 1: 1. In some embodiments, the ratio is in a range of from 1:4 to 1: 1. In some embodiments, the ratio is in a range of from 1:2 to 1: 1. In some embodiments of any of the embodiments described herein, contacting the thin film layer with the amine-containing compound described herein (according to any of the embodiments described herein) is effected by contacting the thin film layer with a solution of the amine-containing compound. In some such embodiments, the solution is an aqueous solution.
In some embodiments of any of the embodiments described herein, a concentration of the amine-containing compound in the solution contacted with the thin film layer is selected such that a desirable boron passage rate (e.g., a boron passage rate according to any of the respective embodiments described herein) is obtained, for example, by selecting a concentration of amine-containing compound which is sufficiently high so as to reduce the boron passage rate of a given thin film layer to a desired range (e.g., to below 20 %, below 15 %, below 12 %, below 10 %, below 8 %, or even below 6 %).
In some embodiments of any of the embodiments described herein, a concentration of the amine-containing compound in the solution contacted with the thin film layer is selected such that a desirable water permeability (e.g., a water permeability according to any of the respective embodiments described herein) is obtained, for example, by selecting a concentration of amine-containing compound which is sufficiently low so as to avoid reducing the water permeability to below a desired minimal level (e.g., 0.2 l-m ^bar ^hour 1).
In some embodiments of any of the embodiments described herein, a concentration of the amine-containing compound (e.g., a compound comprising a relatively large aliphatic hydrocarbon moiety described herein) in the solution contacted with the thin film layer is limited by the solubility of the amine-containing compound (e.g., solubility in aqueous solution), such that the concentration of amine-containing compound is about that of a saturated solution of the amine-containing compound or lower.
In some embodiments of any of the embodiments described herein relating to a process for preparing the water permeable composite membrane, the thin film layer contacted with the solution of amine-containing compound is a degraded thin film layer which has been used to treat water. In some such embodiments, the process for preparing the water permeable composite membrane from the degraded thin film layer is for at least partially restoring the degraded thin film layer.
Herein, the term "degraded" refers to a decrease in a boron rejection and/or salt rejection (i.e., an increase in boron passage and/or salt passage) associated with a thin film layer of a composite membrane (e.g., relative to the same thin film layer prior to use thereof to treat water).
Herein, the "restoring" a degraded thin film layer refers to reversing (at least partially) a change in at least one property associated with the degraded thin film layer (e.g., reversing a decrease in boron rejection and/or a decrease in salt rejection). Upon restoring, the value for the relevant parameter(s) of the thin film layer (e.g., boron rejection and/or salt rejection) moves in a direction of the initial value (e.g., the value prior to use of the thin film layer to treat water). Restoring may optionally be partial, such that upon restoring the value for the relevant parameter(s) of the thin film layer is between the initial value and the value for the degraded thin film layer. Alternatively or additionally, restoring may be complete, such that that the value for the relevant parameter(s) of the thin film layer upon restoring is equal to the initial value, or the initial value is between the value upon restoring and the value for the degraded thin film layer.
In some embodiments of any of the embodiments described herein relating to a degraded thin film layer, the degraded thin film layer is one which has underwent hydrolysis of a portion of the amide bonds in the polyamide therein (e.g., during use of the thin film layer to treat water).
In some embodiments of any of the respective embodiments described herein, the degraded thin film layer is characterized by an increase in boron passage associated with the thin film layer (e.g., relative to the same thin film layer prior to use thereof to treat water). In some such embodiments, the boron passage of the degraded thin film layer is at least 110 % of the boron passage of the thin film layer prior to use thereof in treating water. In some embodiments, the boron passage of the degraded thin film layer is at least 120 % of the boron passage of the thin film layer prior to use thereof in treating water. In some embodiments, the boron passage of the degraded thin film layer is at least 130 % of the boron passage of the thin film layer prior to use thereof in treating water. In some embodiments, the boron passage of the degraded thin film layer is at least 140 % of the boron passage of the thin film layer prior to use thereof in treating water. In some embodiments, the boron passage of the degraded thin film layer is at least 150 % of the boron passage of the thin film layer prior to use thereof in treating water. In some embodiments, the boron passage of the degraded thin film layer is at least 175 % of the boron passage of the thin film layer prior to use thereof in treating water. In some embodiments, the boron passage of the degraded thin film layer is at least 200 % (two-fold) of the boron passage of the thin film layer prior to use thereof in treating water. In some embodiments, the boron passage of the degraded thin film layer is at least 300 % (3-fold) of the boron passage of the thin film layer prior to use thereof in treating water.
In some embodiments of any of the respective embodiments described herein, the degraded thin film layer is one which has been used to treat water at an alkaline pH, for example, in order to facilitate removal of boric acid (e.g., by ionizing boric acid). In some embodiments, the degraded thin film layer is one which has been used to treat water at a pH of at least 8. In some embodiments, the degraded thin film layer is one which has been used to treat water at a pH of at least 8.5. In some embodiments, the degraded thin film layer is one which has been used to treat water at a pH of at least 9. In some embodiments, the degraded thin film layer is one which has been used to treat water at a pH of at least 9.5.
In some embodiments of any of the respective embodiments described herein, the degraded thin film layer is used to treat water which has already passed through one or more other composite membrane, for example, the degraded thin film layer is comprised by a second pass, third pass, and/or fourth pass composite membrane. In some embodiments, the degraded thin film layer is used to treat partially desalinated water (e.g., obtained from seawater) obtained by the aforementioned one or more other composite membrane.
In some embodiments of any of the respective embodiments described herein, the degraded thin film layer is a composite membrane adapted for reverse osmosis of brackish water (e.g., a commercial brackish water reverse osmosis membrane), which has been subsequently degraded. In some such embodiments, a boron rejection rate of the composite membrane (prior to use thereof) is in a range of from 30 % to 80 %. In some embodiments of any of the embodiments described herein relating to a process for preparing the water permeable composite membrane, the thin film layer is contacted with the solution of amine-containing compound in situ, that is, wherein a composite membrane comprising the thin film layer is in functional communication with an apparatus configured for passing water through the composite membrane (e.g., a commercial water treatment apparatus). In some such embodiments, the thin film layer is a degraded thin film layer (e.g., due to use of the composite membrane with the apparatus), which is optionally restored (according to any of the respective embodiments described herein) in situ (e.g., without necessitating removal of the composite membrane from the apparatus).
In some embodiments of any of the embodiments described herein relating to a process for preparing the water permeable composite membrane in situ, preparation is effected by non-covalent binding (e.g., sorption) of the amine-containing compound to the membrane, according to any of the respective embodiments described herein.
Water treatment:
According to an aspect of some embodiments of the invention, there is provided a method of treating water, the method comprising passing water with solutes through a water permeable composite membrane according to any of the respective embodiments described herein, thereby treating the water. In some such embodiments, the solutes include, without limitation, at least one (dissolved) salt and/or boric acid. In some embodiments, the solutes include boric acid. Examples of salts include, without limitation salts comprising an alkali metal cation (e.g., Na+, K+), an alkali earth metal cation (e.g., Mg2+, Ca2+) and/or a halide anion (e.g., CI").
Passing the water with solutes through the water permeable composite membrane according to any of the respective embodiments described herein may optionally be effected by applying a suitable pressure difference between the water on each of the two sides of the membrane (e.g., so as to perform reverse osmosis, in which the applied pressure difference overcomes the osmotic pressure associated with the combination of the membrane and water with solutes), including by applying a greater than atmospheric pressure on one side of the membrane (e.g., using gravity and/or any suitable pumping technique) and/or applying a lower than atmospheric pressure on the other side of the membrane (e.g., using any suitable suction technique). In some embodiments of any of the embodiments described herein relating to a method, treating the water comprises reducing a concentration of boron in the water to less than 1.0 ppm. In some embodiments, treating the water comprises reducing a concentration of boron in the water to less than 0.8 ppm. In some embodiments, treating the water comprises reducing a concentration of boron in the water to less than 0.6 ppm. In some embodiments, treating the water comprises reducing a concentration of boron in the water to less than 0.5 ppm. In some embodiments, treating the water comprises reducing a concentration of boron in the water to less than 0.4 ppm. In some embodiments, treating the water comprises reducing a concentration of boron in the water to less than 0.3 ppm. In some embodiments, treating the water comprises reducing a concentration of boron in the water to less than 0.2 ppm. In some embodiments, treating the water comprises reducing a concentration of boron in the water to less than 0.1 ppm.
Herein, a concentration of a solute in ppm (parts per million) units refers to the weight of solute relative to the weight of sample (e.g., a water sample).
Herein and in the art, a concentration of boron in ppm (parts per million) units refers to the weight of boron atoms relative to the weight of sample (e.g., a water sample with one or more dissolved boron-containing compounds), regardless of what boron- containing compound(s) is present in the sample.
In some embodiments of any of the embodiments described herein relating to a method, passing the water through the water permeable composite membrane is effected no more than three times.
In some embodiments of any of the embodiments described herein relating to a method, passing the water through the water permeable composite membrane is effected no more than twice.
In some embodiments of any of the embodiments described herein relating to a method, passing the water through the water permeable composite membrane is effected no more than once.
A suitable number of times in which water is passed through a water permeable composite membrane (e.g., according to any of the respective embodiments described herein) may be determined by the skilled practitioner based on economic considerations, a desired final concentration of solutes (e.g., boron), and the concentrations and species of solutes in the water to be treated.
In some embodiments of any of the embodiments described herein relating to a method, the water passed through the water permeable composite membrane (according to any of the embodiments described herein) has an alkaline pH, for example, in order to facilitate removal of boric acid (e.g., by ionizing boric acid). In some embodiments, the water has a pH of at least 8. In some embodiments, the water has a pH of at least 8.5. In some embodiments, the water has a pH of at least 9. In some embodiments, the water has a pH of at least 9.5.
In some embodiments of any of the embodiments described herein relating to a method, the method further comprises adjusting a pH of the water to an alkaline pH (a pH according to any of the respective embodiments described herein) and subsequently passing through the water permeable composite membrane. Adjusting the pH may optionally be effected by any suitable technique known in the art, including, for example, addition of a strong base (e.g., NaOH and/or KOH).
In some embodiments of any of the embodiments described herein relating to a method, the method further comprises passing water through an additional water permeable composite membrane prior to or subsequent to passing the water through the water permeable composite membrane according to any of the respective embodiments described herein. The additional water permeable composite membrane may optionally be a water permeable composite membrane according to any of the respective embodiments described herein, or alternatively, a composite membrane known in the art.
In some embodiments of any of the embodiments described herein relating to a method, water is passed through a first water permeable composite membrane (e.g., an additional water permeable membrane) to thereby obtain a partially treated water, prior to passing the (partially treated) water through the water permeable composite membrane (according to any of the embodiments described herein) at an alkaline pH (according to any of the embodiments described herein), and optionally prior to adjusting the pH (according to any of the embodiments described herein) to the aforementioned alkaline pH. In some embodiments, the partially treated water is characterized by a decrease in salt concentration (relative to the salt concentration prior to passing through the first composite membrane), for example, a decrease of at least 50 %, at least 60 %, at least 70 %, at least 80 %, and optionally even at least 90 %. The first water permeable composite membrane is optionally, but not necessarily, a composite membrane according to embodiments of the invention.
In some embodiments, the method comprises passing water through the first water permeable composite membrane to thereby obtain a partially treated water (e.g., according to any of the respective embodiments described herein; adjusting a pH of the partially treated water to an alkaline pH (e.g., of at least 8), according to any of the respective embodiments described herein; and passing the partially treated water with alkaline pH through a second water permeable composite membrane which is a composite membrane according to any of the respective embodiments described herein.
In some embodiments, passing the partially treated water through the second composite membrane (e.g., at an alkaline pH described herein) decreases a boron concentration, by at least 20 %, optionally at least 50 %, optionally at least 60 %, optionally at least 70 %, optionally at least 80 %, and optionally by at least 90 %.
In some embodiments of any of the embodiments described herein relating to a method, the water is passed through at least one water permeable composite membrane which comprises a degraded membrane restored according to a process described herein (e.g., according to any of the respective embodiments). In some embodiments, at least a composite membrane used at an alkaline pH (e.g., according to any of the respective embodiments described herein), for example, a second water permeable composite membrane described herein, comprises a degraded membrane restored according to a process described herein (e.g., according to any of the respective embodiments).
According to an aspect of some embodiments of the invention, there is provided a reverse osmosis apparatus comprising a water permeable composite membrane according to any of the respective embodiments described herein.
The reverse osmosis apparatus is optionally configured to treat water according to any of the respective embodiments described herein relating to a method of treating water.
In some embodiments, the reverse osmosis apparatus is in communication with a reservoir for holding water prior to treatment via passage through the membrane, and/or a reservoir for collecting water treated via passage through the membrane. In some embodiments, the reverse osmosis apparatus is in a functional association with an apparatus configured applying a pressure difference between the water on each of the two sides of the membrane, for example, an apparatus configured for applying a greater than atmospheric pressure to the water on one side of the membrane (e.g., an elevated water reservoir and/or a pump) and/or an apparatus configured for applying a lower than atmospheric pressure to the water on the other side of the membrane (e.g., a pump configured for effecting suction).
Miscellaneous definitions:
As used herein throughout, the term "alkyl" refers to any saturated aliphatic hydrocarbon including straight chain and branched chain groups. Preferably, the alkyl group has 1 to 20 carbon atoms. Whenever a numerical range; e.g., "1-20", is stated herein, it implies that the group, in this case the alkyl group, may contain 1 carbon atom, 2 carbon atoms, 3 carbon atoms, etc., up to and including 20 carbon atoms. More preferably, the alkyl is a medium size alkyl having 1 to 10 carbon atoms. Most preferably, unless otherwise indicated, the alkyl is a lower alkyl having 1 to 4 carbon atoms. The alkyl group may be substituted or non-substituted. When substituted, the substituent group can be, for example, cycloalkyl, aryl, heteroaryl, heteroalicyclic, halo, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, sulfinyl, sulfonyl, cyano, nitro, azide, phosphonyl, phosphinyl, oxo, carbonyl, thiocarbonyl, urea, thiourea, O-carbamyl, N-carbamyl, O-thiocarbamyl, N-thiocarbamyl, C-amido, N-amido, C- carboxy, O-carboxy, sulfonamido, and amino, as these terms are defined herein.
Herein, the term "alkenyl" describes an unsaturated aliphatic hydrocarbon comprise at least one carbon-carbon double bond, including straight chain and branched chain groups. Preferably, the alkenyl group has 2 to 20 carbon atoms. More preferably, the alkenyl is a medium size alkenyl having 2 to 10 carbon atoms. Most preferably, unless otherwise indicated, the alkenyl is a lower alkenyl having 2 to 4 carbon atoms. The alkenyl group may be substituted or non-substituted. Substituted alkenyl may have one or more substituents, whereby each substituent group can independently be, for example, cycloalkyl, alkynyl, aryl, heteroaryl, heteroalicyclic, halo, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, sulfinyl, sulfonyl, cyano, nitro, azide, phosphonyl, phosphinyl, oxo, carbonyl, thiocarbonyl, urea, thiourea, O-carbamyl, N- carbamyl, O-thiocarbamyl, N-thiocarbamyl, C-amido, N-amido, C-carboxy, O-carboxy, sulfonamido, and amino.
Herein, the term "alkynyl" describes an unsaturated aliphatic hydrocarbon comprise at least one carbon-carbon triple bond, including straight chain and branched chain groups. Preferably, the alkynyl group has 2 to 20 carbon atoms. More preferably, the alkynyl is a medium size alkynyl having 2 to 10 carbon atoms. Most preferably, unless otherwise indicated, the alkynyl is a lower alkynyl having 2 to 4 carbon atoms. The alkynyl group may be substituted or non-substituted. Substituted alkynyl may have one or more substituents, whereby each substituent group can independently be, for example, cycloalkyl, alkenyl, aryl, heteroaryl, heteroalicyclic, halo, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, sulfinyl, sulfonyl, cyano, nitro, azide, phosphonyl, phosphinyl, oxo, carbonyl, thiocarbonyl, urea, thiourea, O-carbamyl, N- carbamyl, O-thiocarbamyl, N-thiocarbamyl, C-amido, N-amido, C-carboxy, O-carboxy, sulfonamido, and amino.
A "cycloalkyl" group refers to a saturated on unsaturated all-carbon monocyclic or fused ring (i.e., rings which share an adjacent pair of carbon atoms) group wherein one of more of the rings does not have a completely conjugated pi-electron system. Examples, without limitation, of cycloalkyl groups are cyclopropane, cyclobutane, cyclopentane, cyclopentene, cyclohexane, cyclohexadiene, cycloheptane, cycloheptatriene, and adamantane. A cycloalkyl group may be substituted or non- substituted. When substituted, the substituent group can be, for example, alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heteroaryl, heteroalicyclic, halo, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, sulfinyl, sulfonyl, cyano, nitro, azide, phosphonyl, phosphinyl, oxo, carbonyl, thiocarbonyl, urea, thiourea, O-carbamyl, N- carbamyl, O-thiocarbamyl, N-thiocarbamyl, C-amido, N-amido, C-carboxy, O-carboxy, sulfonamido, and amino, as these terms are defined herein. When a cycloalkyl group is unsaturated, it may comprise at least one carbon-carbon double bond and/or at least one carbon-carbon triple bond.
An "aryl" group refers to an all-carbon monocyclic or fused-ring polycyclic (i.e., rings which share adjacent pairs of carbon atoms) groups having a completely conjugated pi-electron system. Examples, without limitation, of aryl groups are phenyl, naphthalenyl and anthracenyl. The aryl group may be substituted or non-substituted. When substituted, the substituent group can be, for example, alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heteroaryl, heteroalicyclic, halo, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, sulfinyl, sulfonyl, cyano, nitro, azide, phosphonyl, phosphinyl, oxo, carbonyl, thiocarbonyl, urea, thiourea, O-carbamyl, N- carbamyl, O-thiocarbamyl, N-thiocarbamyl, C-amido, N-amido, C-carboxy, O-carboxy, sulfonamido, and amino, as these terms are defined herein.
A "heteroaryl" group refers to a monocyclic or fused ring (i.e., rings which share an adjacent pair of atoms) group having in the ring(s) one or more atoms, such as, for example, nitrogen, oxygen and sulfur and, in addition, having a completely conjugated pi-electron system. Examples, without limitation, of heteroaryl groups include pyrrole, furan, thiophene, imidazole, oxazole, thiazole, pyrazole, pyridine, pyrimidine, quinoline, isoquinoline and purine. The heteroaryl group may be substituted or non- substituted. When substituted, the substituent group can be, for example, alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heteroaryl, heteroalicyclic, halo, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, sulfinyl, sulfonyl, cyano, nitro, azide, phosphonyl, phosphinyl, oxo, carbonyl, thiocarbonyl, urea, thiourea, O-carbamyl, N- carbamyl, O-thiocarbamyl, N-thiocarbamyl, C-amido, N-amido, C-carboxy, O-carboxy, sulfonamido, and amino, as these terms are defined herein.
A "heteroalicyclic" group refers to a monocyclic or fused ring group having in the ring(s) one or more atoms such as nitrogen, oxygen and sulfur. The rings may also have one or more double bonds. However, the rings do not have a completely conjugated pi-electron system. The heteroalicyclic may be substituted or non- substituted. When substituted, the substituted group can be, for example, alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heteroaryl, heteroalicyclic, halo, hydroxy, alkoxy, aryloxy, thiohydroxy, thioalkoxy, thioaryloxy, sulfinyl, sulfonyl, cyano, nitro, azide, phosphonyl, phosphinyl, oxo, carbonyl, thiocarbonyl, urea, thiourea, O-carbamyl, N- carbamyl, O-thiocarbamyl, N-thiocarbamyl, C-amido, N-amido, C-carboxy, O-carboxy, sulfonamido, and amino, as these terms are defined herein. Representative examples are piperidine, piperazine, tetrahydrofuran, tetrahydropyran, morpholine and the like.
An "azide" group refers to a -N=N+=N" group.
An "alkoxy" group refers to both an -O-alkyl and an -O-cycloalkyl group, as defined herein. An "aryloxy" group refers to both an -O-aryl and an -O-heteroaryl group, as defined herein.
A "hydroxy" group refers to a -OH group.
A "thiohydroxy" or "thiol" group refers to a -SH group.
A "thioalkoxy" group refers to both an -S-alkyl group, and an -S-cycloalkyl group, as defined herein.
A "thioaryloxy" group refers to both an -S-aryl and an -S-heteroaryl group, as defined herein.
A "carbonyl" group refers to a -C(=0)-R' group, where R' is defined as hereinabove.
A "thiocarbonyl" group refers to a -C(=S)-R' group, where R' is as defined herein.
A "carboxyl", "carboxylic" or "carboxylate" refers to both "C-carboxy" and O- carboxy".
A "C-carboxy" group refers to a -C(=0)-0-R' groups, where R' is as defined herein.
An "O-carboxy" group refers to an R'C(=0)-0- group, where R' is as defined herein.
A "carboxylic acid" refers to a -C(=0)OH group, including the deprotonated ionic form and salts thereof.
An "oxo" group refers to a =0 group.
A "thiocarboxy" or "thiocarboxylate" group refers to both -C(=S)-0-R' and -O- C(=S)R' groups.
A "halo" group refers to fluorine, chlorine, bromine or iodine.
A "sulfinyl" group refers to an -S(=0)-R' group, where R' is as defined herein. A "sulfonyl" group refers to an -S(=0)2-R' group, where R' is as defined herein. A "sulfonate" group refers to an -S(=0)2-0-R' group, where R' is as defined herein.
A "sulfate" group refers to an -0-S(=0)2-0-R' group, where R' is as defined as herein.
A "sulfonamide" or "sulfonamido" group encompasses both S-sulfonamido and N-sulfonamido groups, as defined herein. An "S-sulfonamido" group refers to a -S(=0)2-NR'R" group, with each of R' and R" as defined herein.
An "N-sulfonamido" group refers to an R' S(=0)2- R" group, where each of R' and R" is as defined herein.
An "O-carbamyl" group refers to an -OC(=0)- R'R" group, where each of R' and R" is as defined herein.
An "N-carbamyl" group refers to an R'OC(=0)-NR"- group, where each of R' and R" is as defined herein.
A "carbamyl" or "carbamate" group encompasses O-carbamyl and N-carbamyl groups.
An "O-thiocarbamyl" group refers to an -OC(=S)-NR'R" group, where each of R' and R" is as defined herein.
An "N-thiocarbamyl" group refers to an R'OC(=S)NR"- group, where each of R' and R" is as defined herein.
A "thiocarbamyl" or "thiocarbamate" group encompasses O-thiocarbamyl and
N-thiocarbamyl groups.
A "C-amido" group refers to a -C(=0)-NR'R" group, where each of R' and R" is as defined herein.
An "N-amido" group refers to an R'C(=0)-NR"- group, where each of R' and R" is as defined herein.
A "urea" group refers to an -N(R')-C(=0)- R"R' " group, where each of R', R" and R" is as defined herein.
A "nitro" group refers to an -NO2 group.
A "cyano" group refers to a -C≡N group.
The term "phosphonyl" or "phosphonate" describes a -P(=0)(OR')(OR") group, with R' and R" as defined hereinabove.
The term "phosphate" describes an -0-P(=0)(OR')(OR") group, with each of R' and R' ' as defined hereinabove.
The term "phosphinyl" describes a -PR'R" group, with each of R' and R" as defined hereinabove.
The term "thiourea" describes a -N(R')-C(=S)- R"R' " group, where each of R', R" and R" is as defined herein. As used herein the term "about" refers to ± 20 %. In some embodiments of any of the embodiments described herein using the term "about", the term "about" is to be interpreted as ± 10 %.
The terms "comprises", "comprising", "includes", "including", "having" and their conjugates mean "including but not limited to".
The term "consisting of means "including and limited to".
The term "consisting essentially of" means that the composition, method or structure may include additional ingredients, steps and/or parts, but only if the additional ingredients, steps and/or parts do not materially alter the basic and novel characteristics of the claimed composition, method or structure.
As used herein, the singular form "a", "an" and "the" include plural references unless the context clearly dictates otherwise. For example, the term "a compound" or "at least one compound" may include a plurality of compounds, including mixtures thereof.
Throughout this application, various embodiments of this invention may be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.
Whenever a numerical range is indicated herein, it is meant to include any cited numeral (fractional or integral) within the indicated range. The phrases "ranging/ranges between" a first indicate number and a second indicate number and "ranging/ranges from" a first indicate number "to" a second indicate number are used herein interchangeably and are meant to include the first and second indicated numbers and all the fractional and integral numerals therebetween.
It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination or as suitable in any other described embodiment of the invention. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements.
Various embodiments and aspects of the present invention as delineated hereinabove and as claimed in the claims section below find experimental support in the following examples.
EXAMPLES
Reference is now made to the following examples, which together with the above descriptions illustrate some embodiments of the invention in a non-limiting fashion. MATERIAL AND METHODS
Materials:
All chemicals were purchased from Aldrich and Acros and used without purification. Double-distilled deionized water (DDW) was used in all experiments.
The fully aromatic polyamide (PA) membranes SWC5 max and SWC4B (Hydranautics) were obtained from Hydranautics, and stored as described by Bernstein et al. [Langmuir 2010, 26: 12358-12365]. The membrane characteristics as specified by the manufacturer - for spiral-wound elements of nominal membrane area 400 ft2 tested using feed solution of 32,000 ppm NaCl, 5 ppm boron, pH 6.5-5 at applied pressure 55 bar and 10% recovery - were as follows:
SWC5 max: boron rejection 92 %, salt rejection 99.8 %, flow rate 37.5 m3/day;
SWC4B: boron rejection 95 %, salt rejection 99.8 %, flow rate 24.6 m3/day.
Before modification, all membranes were first wetted with 50 % ethanol and then with water to ensure complete pore filling. It was verified that such wetting did not affect the membrane performance. The membranes were then tested at feed pressure 55 bar for water permeability using DDW, and for rejection of boric acid and NaCl using a solution of 32,000 ppm NaCl and 5 ppm boron at pH 7-7.3. Membranes which exhibited NaCl rejection below 95 % were discarded. Membrane testing:
Filtration tests were performed in a 150 ml nitrogen-pressurized dead-end stirred cell having a membrane area of 11.3 cm2. Water permeability (Lp) was measured by collecting and weighing the permeate. NaCl concentration in the feed and the permeate was determined from electric conductance of the solutions. Boron concentration was measured using inductively coupled plasma emission spectrometry, using an iCAP 6000 Series device (Thermo Scientific).
The passage (P) of salt and boric acid were each calculated using the relation:
(0) P = Cp / Cf
wherein Cp and C/ are the permeate and feed concentrations, respectively.
Similarly, rejection of salt and boric acid were calculated as 1-P, wherein P is the passage of salt or boric acid, respectively (as described hereinabove).
Surface characterization by infra-red spectroscopy:
Attenuated total reflection Fourier transform infra-red (ATR-FTIR) spectra were recorded (average of 40 scans at 4 cm"1 resolution) on a Nicolet™ 8700 FTIR spectrometer (Thermo -Electron) using a Miracle ATR attachment with a one-reflection diamond-coated KRS-5 element (Pike).
The bands of interests were those of polyamide and polysulfone (at 1660 cm"1 and 1586 cm"1, respectively) of the pristine membrane and the aliphatic CH bands in the region of 2,800-3,000 cm"1 that represent the IR absorption of the modifying molecules (aliphatic amines).
Scanning electron microscopy (SEM):
Surface morphology was evaluated by SEM using a Zeiss Ultra-Plus scanning electron microscope. Prior to imaging, the membrane samples were dried in oven at 30 °C for 12 hours and then coated with gold.
EXAMPLE 1
Effect of covalent coupling of amine-containing compound to polyamide membranes
An RO polyamide membrane (SWC5 max or SWC4B membrane) was mounted in a dead end cell and tested for performance. The cell was then filled with a solution of 0.1 gram of the activator N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC), and activation began and continued for 3 hours at a temperature between 0 and 4 °C, at a pH of 4.6-4.8. At the end of the activation, the membrane was washed several times with double distilled water (DDW), without disassembling the cell, and the EDC solution was replaced by a solution of an amine-containing compound at various concentrations, depending on the tested compound, for 24 hours at 0-4 °C. The membranes were then washed carefully again with DDW and filled with water, and 24 hours later were examined for boron and NaCl rejection and permeability.
The tested amine-containing compounds and some of their pertinent properties are listed in Table 1. Molecular volume, minimum projection area (MPA) and LogP values were obtained at the www(dot)chemicalize(dot)org website.
Propylamine, butylamine, 2-methyl-butylamine, amylamine, hexylamine and tert-octylamine were reacted with an SWC5 max membrane, and decylamine and dodecylamine were reacted with a SWC4B membrane.
The use of EDC allows covalent coupling (via amide bond formation) of the amine-containing compounds to free carboxylic acid groups in the polyamide of the membranes (depicted in FIG. 1), although ionic bonds between positively charged amine groups and negatively charged carboxylic groups and/or hydrophobic interactions between polyamide and the hydrocarbon tail of amine-containing compounds may also be present.
Table 1: Exemplary amine-containing compounds and properties thereof
Minimum
Compound Projection Molecular
Mw
Area Volume LogP [g/mole]
(MPA)
Name No. [A3]
[A2]
n-propylamine C3 59.11 18.07 74.07 0.25 n-butylamine C4 73.14 19.75 91.05 0.70
2-methyl-n-butylamine C5* 87.16 26.51 108.28 1.06 amylamine
C5 87.16 20.14 108.02 1.14 (n-pentylamine)
n-hexylamine C6 101.19 21.44 124.99 1.59 phenethylamine
C8 121.18 25.92 127.80 1.39 (2-phenyl-ethylamine) tert-octylamine
(2-methyl-heptyl-2- C8* 129.24 31.79 159.97 1.98 amine)
n-decylamine CIO 157.30 26.49 192.98 3.37 n-dodecylamine C12 185.35 26.90 226.98 4.25
In a preliminary experiment using 50.2 mM of 2-methyl-butylamine (a relatively small compound) in solution, an excessive drop in membrane water permeability was observed. Subsequent experiments with various amine-containing compounds therefore used a concentration of 15.64 mM. This resulted in an acceptable drop in water permeability upon modification using the shorter amines, C3-C6 and C8*; however, for the longer amines, CIO and C12, the water permeability was reduced a near zero value (data not shown), suggesting that excessive uptake of alkylamine renders the membrane sufficiently hydrophobic so as to be virtually impermeable to water. To mitigate the loss of permeability, in subsequent experiments, the solution concentrations for the relatively long amylamine, hexylamine, decylamine and dodecylamine were further reduced to 1.04 mM.
These results indicate that amine-containing compounds with a relatively high hydrophobicity (e.g., as indicated by logP value) more efficiently bind to the polyamide membrane than do more hydrophilic amine-containing compounds, and that low solution concentrations of relatively hydrophobic amine-containing compounds result in a similar degree of binding as do higher solution concentrations of more hydrophilic amine-containing compounds.
As shown in FIG. 2, treatment of the polyamide membrane with any of the amine-containing compounds reduced water permeability of the membrane.
As further shown in FIG. 2, 15.64 mM of propylamine, butylamine, 2-methyl- butylamine and tert-octylamine had an effect comparable to that of a lower concentration (1.04 mM) of amylamine, hexylamine or decylamine, whereas treatment with even a low concentration (1.04 mM) of dodecylamine resulted in the greatest reduction in water permeability. These results indicate that relatively short and/or branched amine-containing compounds reduce water permeability to a lesser degree than do longer, linear amine- containing compounds.
As shown in FIG. 3, treatment of the polyamide membrane with each of the amine-containing compounds reduced the boron permeability of the membrane by over 50 %. As further shown therein, with the exception of tert-octylamine, there was an overall trend whereby selectivity steadily improved as the alkylamine length increased, and boron permeability was reduced by over 80 % by treatment with CIO and C12 amine-containing compounds.
In addition, NaCl rejection was also enhanced by treatment with amine- containing compounds, although to a lesser degree than boron rejection enhancement (data not shown).
These results indicate that hydrophobicity and size of amine-containing compounds correlate with membrane selectivity.
As shown in FIG. 4, with the exception of tert-octylamine, the reduction in boron permeability was correlated to the MPA.
Tert-octylamine exhibited the highest MPA among the tested amine-containing compounds (about 32 A2, as opposed to about 18-27 A2 for the other compounds), but does not exhibit an exceptional LogP or molecular volume in comparison with the other tested compounds. This result suggests that the relatively large molecular width and/or MPA of compounds such as tert-octylamine result in a considerably reduced ability to penetrate nano-pores, thereby having less of an effect on boron permeability. In contrast, another branched molecule, 2-methyl-butylamine (C5*), behaved similarly to linear alkylamines in reducing boron permeability to an extent correlated with MPA, suggesting that its smaller MPA and width (intermediate between tert-octylamine and linear alkylamines) allows uptake into nano-pores and considerable modification of the membrane.
The above results indicate that molecular width and/or MPA of the amine- containing compounds is an important factor in affecting boron permeability, and that amine-containing compounds exhibiting a low MPA (e.g., up to about 27-30 A2), such as linear alkylamines, are particularly suitable for reducing boron permeability of membranes. Linear alkylamines have a width of about 0.3-0.5 nm, which is only weakly dependent on the length. Such compounds are therefore narrow enough to closely fit in narrow pores, converting the remaining free pore volume into significantly narrower and more hydrophobic (less polar) channels.
Phenethylamine, which differs from the other amine-containing compounds in that it is aromatic, did not enhance rejection, similarly to the aliphatic amines (data not shown). Indeed, rejection of NaCl and boron often decreased after modification with phenethylamine. Moreover, treatment with relatively high concentrations of phenethylamine resulted in visible damage to the membrane, suggesting that the polysulfone layer was affected.
This result suggests that aromatic amines do not significantly alter the chemistry around pores, possibly because they are too similar in structure to the unmodified aromatic polyamide and/or because of their considerable polarizability. The greater width of aromatic amines versus linear aliphatic amines may also limit the ability of aromatic amines to enter and interact with pores.
ATR-FTIR spectroscopy was used to directly detect the uptake of aliphatic amines.
As shown in FIG. 5, uptake of aliphatic amines was observable as aliphatic C-H stretching bands emerging in the 2800-3000 cm"1 region, where aromatic polyamide and polysulfone exhibited little or no absorption.
As further shown in FIG. 5, uptake of dodecylamine resulted in larger aliphatic C-H stretching bands than did uptake of propylamine, which is consistent with the larger size and greater hydrophobicity of the dodecylamine aliphatic moiety in comparison with the propylamine aliphatic moiety.
The ATR-FTIR spectrum did not change significantly after a 48 hour wash, during which the membranes were soaked in hot boiled water at 60 °C with water exchanged several times (data not shown). These results indicate that the amine- containing compound was strongly bound to the polyamide membrane, confirming the formation of amide bonds.
As further shown in FIG. 5, the spectrum upon aliphatic amine uptake was not much affected in spectral regions other than the 2800-3000 cm"1 region. An exception was a small band which emerged at 1720 cm"1, which was assigned to the carbonyl group of an ionized carboxylic group of polyamide.
This result indicates that the membrane was not damaged or chemically altered, and further suggests that amine uptake resulted in ionization of the carboxylic groups, which could in turn contribute to immobilization of the amine via ionic bonds.
Uptake of decylamine and dodecylamine was also detected by measuring water contact angles of the membranes before and after treatment. The water contact angle of untreated SWC4B membranes was 42.0° + 2.4°, whereas the water contact angle of SWC4B membranes treated with decylamine was 54.3° + 1.9° and the water contact angle of SWC4B membranes treated with dodecylamine was 51.1° + 2.3°.
These results indicate that uptake by an activated membrane of long aliphatic amines results in a more hydrophobic membrane, suggesting that the hydrophobic aliphatic moieties tend to face outwards, and the amine groups tend to be less exposed to the surface, being covalently bound to the polyamide by amide bonds.
EXAMPLE 2
Effect of sorption of amine-containing compound to polyamide membranes
An RO polyamide membrane (SWC4B membrane) was mounted in a dead end cell and tested for performance. The cell was then filled with a solution of a tested amine-containing compound, and the solution was filtered for about an hour at a pressure of 55 bar. The solution was then removed and the system was washed with DDW without dissembling the cell, soaked in DDW for 24 hours, and then examined again for boron and NaCl rejection and permeability.
The above procedure does not promote covalent binding of the amine-containing compounds to the membrane, but does allow formation of ionic bonds between positively charged amine groups and negatively charged carboxylic groups, as well as physical sorption (e.g., by hydrophobic interactions).
As shown in FIG. 6, sorption of amylamine and hexylamine did not reduce boron permeability in the absence of carbodiimide activation, whereas sorption of decylamine and dodecylamine considerably reduced boron permeability, although to a somewhat lesser degree than in the presence of carbodiimide activation. These results indicate that the covalent bonds formed upon carbodiimide activation exhibit a significant effect on boron permeability, but that for longer amines (e.g., decylamine and dodecylamine), non-covalent sorption also plays an important role in reducing boron permeability.
EXAMPLE 3
Effect of poly amide membrane modification on tradeoff between boron rejection and water permeability
As any type of membrane can be modified so as to simultaneously increase or reduce solute passage and water permeability - for example, by adjusting the effective thickness of the membrane - RO membranes may generally be characterized by a tradeoff between selectivity (associated with effective removal of solutes) and flux (associated with water permeability). Similarly, a successful modification of a membrane may be characterized by an improved flux-selectivity tradeoff.
The relationship between boron rejection and water permeability of the various modified membranes prepared as described in Examples 1 and 2 were compared, by plotting boron passage as a function of water permeability (in the presence of 32,000 ppm NaCl and 5 ppm boron). In such a plot, an improved tradeoff is characterized by a downward (lower solute passage) and/or rightward trend (higher water permeability).
Commercial elements usually exhibit much better selectivity for elements than for small flat- sheet coupons in dead-end cells, which were employed in the above examples. Specifically, the boron passage of seawater RO membranes as commercial spiral-wound elements is usually 8-10 %, whereas in dead-end cells it was around 30-40 %. The difference is believed to be due to different hydrodynamic and concentration polarization conditions in the cells, possible differences in membrane post-treatment and minor damage or defects sustained by small flat sheet samples. For this reason, modified membranes in this example were compared to the pristine membranes tested in the dead-end cells under the same conditions.
As shown in FIG. 7, modified membranes exhibited a ratio of boron passage to water permeability (in the presence of 32,000 ppm NaCl and 5 ppm boron) which was similar to or reduced in comparison to unmodified commercial SWC5 max and SWC4B membranes. As further shown therein, the improvement in boron rejection relative to water permeability was greatest for the longest tested alkylamines (e.g., decylamine and dodecylamine), which reduced the ratio of boron passage to water permeability considerably upon either covalent binding or adsorption, as well as for a branched alkylamine (2-methyl-butylamine) having an almost identical MPA.
As further shown therein, the improvement in boron rejection relative to water permeability was usually greater for covalently bound alkylamines than for adsorbed alkylamines.
These results indicate that modification of RO membranes as described herein advantageously improves rejection of boron for a given water permeability, especially when long amine-containing compounds are used.
EXAMPLE 4
In situ poly amide membrane modification
In order to confirm that results such as obtained hereinabove using small flat sheet membrane samples in dead-end cells can also be obtained at industrial scales, polyamide membrane modification such as described hereinabove was performed in situ on commercial RO modules.
Fully aromatic polyamide (PA) membrane spiral-wound Filmtec™ SW30-2540 elements of nominal membrane area 2.8 m2 were obtained from Dow and stored according to the manufacturer's recommendations. The membrane characteristics as specified by the manufacturer were as follows: boron rejection 91 %, salt rejection 99.4 %, flow rate 2.6 m3/day.
In situ modification of spiral wound membrane elements and the filtration experiments were performed in a pilot unit depicted schematically in FIG. 8. The setup included a 200 liter feed tank, a 2540 membrane element mounted in a stainless steel pressure vessel (M-1), a high pressure pump with an auxiliary feed pump, a feed pressure gauge (PI-1) and a control valve with a pressure gauge located in the concentrate line (PI-2). The water fluxes were monitored using flow-meters installed in the feed and permeate lines. The water temperature was controlled and monitored using a heat exchanger (HE-1) equipped with a thermometer. The system was operated in a closed loop returning the permeate and concentrate back to the feed tank. Filtration tests were performed on the RO pilot system depicted schematically in FIG. 8. A Filmtec™ SW30 RO membrane was mounted in the RO system and initial performance was tested, as follows. First, the membrane was compacted at 20 bar for 2 hours and the pure water permeability was measured at feed pressure of 40 bar and concentrate flow of 500 liters/hour. Pure water was then replaced with a solution of 15,000 ppm NaCl and 5 ppm boron (in the form of added boric acid) at pH 7-7.3; and the membrane performance, including NaCl and B rejection and volumetric flux, was tested at a feed pressure of 40 bar, keeping the recovery in the range 13-16 %.
Permeate and feed samples were collected and measured every 30 minutes before modification and after washing stage followed the modification. The permeability was determined according to the formula:
where V is the permeate volume collected over time t; A is the membrane surface area in the element as reported by the manufacturer (2.8 m2); P is the applied transmembrane pressure difference; and π is the osmotic pressure difference which was calculated using the van 't Hoff equation.
Thereafter, the membrane was treated using solutions of one of the aliphatic amine molecules at concentrations of 0.1, 0.5, 1 and 2 mM, in order to effect sorption of the amine. For each element modifying solutions of a specific amine were applied starting from lowest concentration (0.1 mM) up to the highest concentration (2 mM). After each concentration the system was washed with pure water and performance of the membrane was tested as described hereinabove. Aliphatic amines with a long aliphatic tail, n-decylamine and n-dodecylamine, were tested, as these amines exhibited the strongest effects in laboratory- scale experiments described hereinabove. However, the shorter n-alkylamines, amylamine (n-pentylamine) and n-octylamine, were tested as well for comparison. The tested compounds and their properties are summarized in Table 2. Table 2: Exemplary amine-containing compounds and properties thereof
Figure imgf000080_0001
As shown in FIG. 9A, decylamine considerably enhanced membrane selectivity in a concentration-dependent manner at all concentrations tested (up to 2 mM, which is below the water solubility of decylamine (3.5 mM)), with boron passage being reduced to a greater extent (from about 9-10 % to about 2 %) than water permeability.
Similarly, as shown in FIG. 9B, dodecylamine considerably decreased membrane boron passage in a concentration-dependent manner up to a concentration of 1 mM, from about 9-10 % to about 5 %.
However, as further shown in FIG. 9B, increasing dodecylamine concentration to 2 mM resulted in a considerable reduction in water permeability with little change in boron rejection.
As such concentrations are above the water solubility of dodecylamine (0.42 mM), a portion of the dodecylamine in the solution may be in the form of micelles (which may potentially foul the membrane by depositing on the membrane surface), and increasing the concentration from 1 mM to 2 mM may add to the micelle phase without altering the concentration of free molecules.
The above results suggest that maximal or near-maximal boron rejection is obtained at or slightly above the solubility limit of an alkylamine, and that further increases in alkylamine concentration may harm performance by reducing water permeability without further enhancing boron rejection.
In comparison, amylamine and n-octylamine had little effect on boron passage or water permeability (data not shown), suggesting that the solubility of these alkylamines was too high to result in significant partitioning to the polyamide in this setup and/or that the lower hydrophobicity of the alkylamines was insufficient to alter polyamide properties significantly.
Furthermore, as shown in FIGs. 9 A and 9B, modification by an aliphatic amine reduces water permeability in a manner which is correlated to both amine concentration and molecular size of the amine. Accordingly, the relatively small amylamine and n- octylamine had little effect on water permeability (data not shown).
In contrast to the above-described effects of membrane modification on boron passage and water permeability, as shown in FIGs. 10A and 10B, salt passage was not significantly effected by any of the tested alkylamines at concentrations in the range of 0.1 to 2 mM.
These results indicate that modification of RO membranes by amine-containing compounds has little or no effect on salt passage.
These results indicate that boron passage can be reduced by a factor of 2 to 5 (by 50 % to 80 %), while maintaining a water permeability within acceptable ranges for seawater RO, and without significant changes in salt rejection.
After performance testing, the modules were cut open and membrane samples were taken from different parts of the module for surface characterization.
ATR-FTIR was used to directly detect the uptake of aliphatic amines, according to procedures described in the Materials and Methods section hereinabove.
As shown in FIG. 11, dodecylamine and dodecylamine uptake was observed as similar aliphatic C-H stretching bands emerging in the 2800-3000 cm"1 region, in which aromatic polyamide and polysulfone support have little or no IR absorption. As further shown therein, the IR spectrum did not show significant changes in regions other than 2800-3000 cm"1, indicating that the membrane was not damaged or chemically altered.
Furthermore, IR spectra the obtained from the front, back and middle areas of the module were similar (data not shown), indicating that was similar modification of the polyamide membrane was relatively uniform between different portions of the module.
The effects of modification on polyamide surfaces was further examined using scanning electron microscopy (SEM) in order to assess surface morphology, as described in the Materials and Methods section hereinabove. As shown in FIGs. 12A and 12B, modified polyamide membrane surfaces exhibited the characteristic ridge-and-valley morphology of pristine polyamide membrane surfaces, indicating that the morphology of the polyamide top-layer was unaffected by modification.
As the RO membranes in general show a correlation between boron passage and water permeability, i.e., born rejection is enhanced when membranes are less permeable, the significance of modification was evaluated on a tradeoff plot, showing both boron passage and water permeability.
As shown in FIG. 13, modification with decylamine or dodecylamine resulted in a substantial beneficial shift in tradeoff, wherein a considerable decrease in boron passage offsets a moderate decrease in water permeability.
The above results indicate that in situ modification of commercial spiral-wound elements via sorption of aliphatic amines, especially long chain amines such as decylamine and dodecylamine near their solubility limit, may lead to an improvement in boron rejection and permeability-selectivity tradeoff, similarly to results obtained in laboratory-scale experiments herein. Furthermore, such sorption can be effected in working installations (such as existing RO plants) using a fairly simple filtration procedure and minimal amounts of chemicals, and the performance of SWRO membranes could be tuned and tailored for specific needs, e.g., by modulating amine concentration.
EXAMPLE 5
Effect of modification by amine-containing compound on damaged polyamide membranes
Hydrolysis in polyamide membranes may occur upon exposure to alkaline solutions. Although manufacturer's commonly claim that membrane performance is not affected between a pH 1-2 and a pH of 10-11, relevant data is scarce.
A serious deterioration of salt and boron rejection was observed for brackish water reverse osmosis (BWRO) membranes operating at a second pass of a commercial seawater desalination plant, after exposure to a relatively high pH (pH > 9) for several months. The high pH is used to ionize boric acid, to thereby facilitate boron removal in the second pass, after seawater has been converted to brackish water in the first pass.
As hydrolysis of polyamide generates free carboxylic acid groups, thereby increasing hydrophilicity and decreasing polyamide crosslinking, it was hypothesized that covalent or non-covalent binding of amine groups of an amine-containing compound to a thus-generated free carboxylic acid group may at least partially reverse the effects of hydrolysis.
In order to obtain a brackish water RO membrane with controlled and well defined hydrolysis-induced damage, BW30 membranes (Dow) were exposed to NaOH solutions with pH 11 for 24 hours, followed by a wash with distilled water. The characteristics of the pristine BW30 membrane as specified by the manufacturer were as follows: boron rejection 65 %, salt rejection 99.5 %, flow rate 40.08 m3/day.
Membranes pre-treated at pH 11 in this manner served as a model for membranes damaged by months of use at more moderately alkaline conditions. The membrane was mounted in a dead end cell and tested for initial performance (boron passage, salt passage, and water flux) was tested at a pH in a range of 7.0 to 7.3, using procedures described hereinabove.
Following hydrolysis at pH 11 and initial performance testing, the damaged brackish water RO membranes were subjected to sorption of decylamine or hexadecylamine. Covalent coupling and sorption of decylamine are exemplified hereinabove, and hexadecylamine allows examination of the effects of longer aliphatic amines. The tested compounds and their properties are summarized in Table 3. Modification was effected by carbodiimide-based covalent coupling or by sorption, according to procedures described hereinabove. Following modification, performance (boron passage, salt passage, and water flux) was tested again, using procedures described hereinabove.
Table 3: Exemplary amine-containing compounds and properties thereof
Minimum
Compound Projection Molecular
Mw
Area Volume LogP pKa [g/mole]
(MPA)
Name No. [A3]
[A2]
n-decylamine CIO 157.30 26.49 192.98 3.37 10.64 n-hexadecylamine C16 241.46 31.24 294.98 6.03 10.61 As shown in FIGs. 14A and 14B, hydrolysis at pH 11 resulted in an increase of both salt passage and boron passage, and decylamine treatment by either covalent coupling (FIG. 14A) or sorption (FIG. 14B) reversed the effect of hydrolysis by reducing salt passage and boron passage levels to those of a pristine membrane (via sorption, FIG. 14B) or even lower (via covalent coupling, FIG. 14A).
As shown in FIGs. 15A and 15B, hexadecylamine treatment by covalent coupling (FIG. 15A) or by sorption (FIG. 15B) reversed the hydrolysis-induced increase in salt passage and boron passage, by reducing salt passage and boron passage levels even lower than of those of a pristine membrane.
The above results for hexadecylamine are similar to those for decylamine, except that sorption of hexadecylamine was more effective than sorption of decylamine in reducing salt and boron passage. These results indicate that the lower water solubility of hexadecylamine (0.0013 mM) as compared to decylamine (3.5 mM) enhances immobilization in the membrane via sorption.
Taken together, the above results indicate that polyamide membranes damaged by hydrolysis (e.g., at alkaline pH) can be repaired (at least partially), using amine - containing compounds to modify the membrane.
Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.
All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention. To the extent that section headings are used, they should not be construed as necessarily limiting.

Claims

WHAT IS CLAIMED IS:
1. A water permeable composite membrane comprising a thin film layer on a porous substrate, the thin film comprising a polymer and amine-containing compound associated with the polymer, said amine-containing compound comprising at least one aliphatic hydrocarbon moiety attached to an amine group.
2. The composite membrane of claim 1, wherein said polymer comprises a poly amide.
3. The composite membrane of claim 1 or 2, wherein said aliphatic hydrocarbon moiety is from 1 to 30 carbon atoms in length, being saturated or unsaturated, and substituted or unsubstituted.
4. The composite membrane of any one of claims 1 to 3, wherein said aliphatic hydrocarbon moiety is at least 3 carbon atoms in length.
5. The composite membrane of any one of claims 1 to 4, wherein said aliphatic hydrocarbon moiety contains at least 8 carbon atoms.
6. The composite membrane of any one of claims 1 to 5, wherein said amine-containing compound has the general formula:
Figure imgf000085_0001
wherein:
Ri is said aliphatic hydrocarbon moiety; and
R2 and R3 are each independently selected from the group consisting of hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, and a heteroalicyclic, or, alternatively, one or both of R2 and R3 is independently a covalent bond linking the amine-containing compound to said polymer or a group participating in a covalent bond linking the amine- containing compound to said polymer.
7. The composite membrane of any one of claims 1 to 6, wherein said amine-containing compound is associated with the polymer via an amide bond to said polymer.
8. The composite membrane of claim 6, wherein at least one of R2 and R3 is a covalent bond linking the amine-containing compound to said polymer or a group participating in a covalent bond linking the amine-containing compound to said polymer.
9. The composite membrane of claim 6 or 8, wherein R2 and/or R3 is an amide bond with a carboxylic group in said polymer.
10. The composite membrane of claim 9, wherein R2 is hydrogen and R3 is said amide bond.
11. The composite membrane of any one of claims 1 to 6, wherein said amine-containing compound is associated with said polymer via non-covalent interactions.
12. The composite membrane of claim 6, wherein R2 and R3 are each independently selected from the group consisting of hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, and a heteroalicyclic.
13. The composite membrane of claim 12, wherein R2 and R3 are each hydrogen.
14. The composite membrane of any one of claims 11 to 13, wherein said aliphatic hydrocarbon moiety is at least 5 carbon atoms in length.
15. The composite membrane of any one of claims 6, 8 to 10, 12 and 13, wherein Ri is at least 8 carbon atoms in length.
16. The composite membrane of any one of claims 6, 8 to 10 and 12 to 15, wherein Ri consists of a linear aliphatic hydrocarbon moiety which is unsubstituted or is substituted by one or more substituents selected from the group consisting of alkyl, alkenyl, alkynyl, cycloalkyl, heteroalicyclic, halo, hydroxy, alkoxy, thiohydroxy, thioalkoxy, sulfinyl, sulfonyl, cyano, nitro, azide, phosphonyl, phosphinyl, oxo, carbonyl, thiocarbonyl, urea, thiourea, O-carbamyl, N-carbamyl, O-thiocarbamyl, N- thiocarbamyl, C-amido, N-amido, C-carboxy, O-carboxy, sulfonamido, and amino.
17. The composite membrane of claim 16, wherein when said linear aliphatic hydrocarbon is substituted, each of said one or more substituents is no more than 3 atoms in length.
18. The composite membrane of claim 17, wherein said one or more substituents are each independently selected from the group consisting of methyl, halo, hydroxy, thiohydroxy, oxo, and -NH2.
19. The composite membrane of any one of claims 16 to 17, wherein said one or more substituents are selected from the group consisting of alkyl, alkenyl, alkynyl, cycloalkyl, and halo.
20. The composite membrane of any one of claims 16 to 19, wherein said linear aliphatic hydrocarbon moiety is substituted by no more than two substituents.
21. The composite membrane of claim 20, wherein said linear aliphatic hydrocarbon moiety is substituted by no more than one substituent.
22. The composite membrane of any one of claims 16 to 20, wherein said linear aliphatic hydrocarbon moiety comprises no more than one substituent attached to each carbon atom in said linear aliphatic hydrocarbon moiety.
23. The composite membrane of any one of claims 1 to 22, wherein a LogP of said amine-containing compound is at least 0.2.
24. The composite membrane of claim 23, wherein a LogP of said amine- containing compound is at least 1.0.
25. The composite membrane of any one of claims 23 and 24, wherein a LogP of said amine-containing compound is no more than 6.0.
26. The composite membrane of any one of claims 1 to 22, wherein a minimum projection area of said amine-containing compound is no more than 30 A2.
27. The composite membrane of claim 26, wherein a minimum projection area of said amine-containing compound is at least 18 A2.
28. The composite membrane of any one of claims 1 to 27, wherein a boron passage rate of the composite membrane is less than 80 % of a boron passage rate of a corresponding composite membrane without said amine-containing compound covalently and/or non-covalently bound to said polymer, wherein said boron passage rate is determined using an aqueous solution of boric acid and NaCl with 32,000 ppm NaCl and 5 ppm boron, at pH 7, and at a feed pressure of 55 bar.
29. The composite membrane of any one of claims 1 to 28, wherein a water permeability of the composite membrane is at least 20 % of a water permeability of a corresponding composite membrane without said amine-containing compound covalently and/or non-covalently bound to said polymer, wherein said water permeability is determined using an aqueous solution of boric acid and NaCl with 32,000 ppm NaCl and 5 ppm boron, at pH 7, and at a feed pressure of 55 bar.
30. The composite membrane of any one of claims 1 to 29, wherein a boron passage rate of the composite membrane is less than 20 %, wherein said boron passage rate is determined using an aqueous solution of boric acid and NaCl with 32,000 ppm NaCl and 5 ppm boron, at pH 7, and at a feed pressure of 55 bar.
31. The composite membrane of any one of claims 1 to 30, wherein a water permeability of the composite membrane is at least 0.2 liters per square meter per bar per hour (l-m ^bar ^hour 1), wherein said water permeability is determined using an aqueous solution of boric acid and NaCl with 32,000 ppm NaCl and 5 ppm boron, at pH 7, and at a feed pressure of 55 bar.
32. The composite membrane of any one of claims 1 to 31, wherein a ratio of a boron passage rate to water permeability of the composite membrane is less than 90 % of a ratio of a boron passage rate to water permeability of a corresponding composite membrane without said amine-containing compound covalently and/or non-covalently bound to said polymer, wherein said boron passage rate and said water permeability are determined using an aqueous solution of boric acid and NaCl with 32,000 ppm NaCl and 5 ppm boron, at pH 7, and at a feed pressure of 55 bar.
33. The composite membrane of any one of claims 1 to 32, wherein a ratio of a boron passage rate to water permeability of the composite membrane is less than 30 % boron passage rate per 1.0 liter per square meter per bar per hour water permeability (30 % per l-m ^bar ^hour 1), wherein said boron passage rate and said water permeability are determined using an aqueous solution of boric acid and NaCl with 32,000 ppm NaCl and 5 ppm boron, at pH 7, and at a feed pressure of 55 bar.
34. A process for preparing the water permeable composite membrane of any one of claims 1 to 33, the process comprising contacting a thin film layer comprising said polymer with said amine-containing compound.
35. The process of claim 34, wherein said polymer comprises free carboxylic acid groups, the process further comprising contacting the thin film layer with an activator of carboxylic acid groups, said activator being selected as being capable of forming an amide bond between carboxylic acid groups and amine groups.
36. The process of claim 34, wherein a ratio of free carboxylic acid groups to amide groups in said polymer prior to contacting said thin film layer with said activator of carboxylic acid groups is in a range of from 1:50 to 1: 1 (free carboxylic acid:amide).
37. The process of any one of claims 34 to 36, wherein said contacting is effected using a solution of said amine-containing compound, wherein a concentration of said amine-containing compound in said solution is selected such that a water permeability of the composite membrane is at least 0.2 liters per square meter per bar per hour (l-m ^bar ^hour 1), wherein said water permeability is determined using an aqueous solution of boric acid and NaCl with 32,000 ppm NaCl and 5 ppm boron, at pH 7, and at a feed pressure of 55 bar.
38. The process of any one of claims 34 to 37, wherein said thin film layer is degraded following use thereof to treat water, the process being for at least partially restoring the degraded thin film layer.
39. The process of claim 38, wherein said thin film layer is degraded following use thereof at a pH of at least 8.
40. A reverse osmosis apparatus comprising the water permeable composite membrane of any one of claims 1 to 33.
41. A method of treating water, the method comprising passing water with solutes through the water permeable composite membrane of any one of claims 1 to 33, thereby treating the water.
42. The method of claim 41, wherein treating the water comprises reducing a concentration of boron in the water to less than 0.5 ppm.
43. The method of claim 41 or 42, wherein passing the water through said water permeable composite membrane is effected no more than once.
44. The method of claim 41 or 42, wherein said water with solutes has a pH of at least 8.
45. The method of claim 44, comprising:
passing water with solutes through a first water permeable composite membrane, to thereby obtain a partially treated water;
adjusting a pH of said partially treated water to at least 8, to thereby obtain said water with solutes having said pH of at least 8; and
passing said water with solutes having said pH of at least 8 through a second water permeable composite membrane which is a water permeable composite membrane according to any one of claims 1 to 33,
thereby treating the water.
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