CN101596419B - Polyvinylidene fluoride/liquid crystal blending microporous membrane and preparation method thereof - Google Patents
Polyvinylidene fluoride/liquid crystal blending microporous membrane and preparation method thereof Download PDFInfo
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- CN101596419B CN101596419B CN2009100694859A CN200910069485A CN101596419B CN 101596419 B CN101596419 B CN 101596419B CN 2009100694859 A CN2009100694859 A CN 2009100694859A CN 200910069485 A CN200910069485 A CN 200910069485A CN 101596419 B CN101596419 B CN 101596419B
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Abstract
The invention discloses a polyvinylidene fluoride/liquid crystal blending microporous membrane and a preparation method thereof. The microporous membrane comprises the following components by mass percentage (wt%):10-30% of polyvinylidene fluoride, 0.4-4% of macromolecule lyotropic liquid crystal, 56-88.6% of organic solvent and 1-10% of additive. The preparation method comprises the following components of the microporous membrane by mass percentage (wt%) and the following steps: (1) 25-27% of cyanoethyl cellulose or cyanoethyl-ethyl cellulose is dissolved into 25-75% of N,N-dimethyl fomamide, N,N-dimethyl acetamide, N,N-dimethyl sulfoxide, glacial acetic acid or crylic acid, is put in constant temperature of 50 DEG C for 12 hours, and is stood for 72 hours at room temperature to form lyotropic liquid crystal; (2) microporous membrane components are weighted; (3) the organic solvent, polyvinylidene fluoride and additive are evenly mixed, and then the lyotropic liquid crystal is added to form membrane forming liquid; (4) the traditional technology and devices are used for weaving a hollow-fibre membrane or a striking flat membrane; and (5) the obtained microporous membrane is dipped in protection liquid for 3-24 hours to obtain the microporous membrane of the invention.
Description
Technical field
The present invention relates to the organic membrane technology of macromolecule, be specially a kind of Kynoar/liquid crystal blending microporous membrane and preparation method who is used for water treatment and chemical separation process.
Background technology
Diffusion barrier has separation concurrently, concentrates, purifying and refining function, efficient, energy-saving and environmental protection is arranged again, molecular level filters and process is simple, be easy to characteristic such as automation control, is the optimization technique of 21 century drinking water treatment.Film is the core of membrane technology, and separation process plays decisive role to film for the chemical property of membrane material and membrane structure.Kynoar (PVDF) has advantages such as good hear resistance, chemical stability and radiation hardness.Therefore, PVDF particularly in micro-filtration membrane and milipore filter field, has been widely used in industries such as chemical industry, electronics, weaving and food as extremely people's favor of membrane material.However, PVDF is owing to have extremely low surface energy, make it have extremely strong hydrophobicity, when carrying out the separation of materials such as oil/water, protein, cause film to pollute easily, cause membrane flux significantly to descend, separating property changes, and cleans energy consumption and strengthens, film reduces service life, and operation cost increases.In the film separation process of reality, the pollution of film can not be eliminated fully, and along with the prolongation of operating time, the flux of film can reduce thereupon.But by the pollution level that reduces film that different pollution condition is taken appropriate measures is feasible.Because the environment difference of membrane process, the reason that produces the film pollution is a lot, and therefore film contamination phenomenon more complicated, also is not applicable to the universal method that solves various film pollution situations at present.Only catch the principal element that causes film pollution and concentration polarization, effectively controlling diaphragm pollutes, thereby reduces the cleaning frequency of film, the effective time of prolongation film, improves production capacity and efficient.
At present, the method to the pvdf membrane modification mainly contains membrane surface modification and membrane material modified.Membrane surface modification comprises that the modification of film chemical surface treatment, film are surface recombination modified, the modification of film surface plasma and film surface grafting modification etc.But, these method of modifying all have certain defective: for example, film surface-coated predetermined substance carries out the method for membrane surface modification to pvdf membrane, and the greatest problem of this method is exactly to add or the reception or the block copolymer that apply easily break away from from the pvdf membrane surface, can not obtain permanent modified effect; Again for example, plasma or irradiation grafting are at the method for modifying on pvdf membrane surface, because the macromolecular crosslinked heat endurance of pvdf membrane that makes descends to some extent on the film surface, and needs long back condensation process after the grafting, have increased the manufacturing cost of film.In addition, membrane surface modification has only been modified the film surface, membrane pore structure is not related to, so pollutant still can accumulate in the fenestra road, causes film to pollute.
The modification of membrane material mainly is to prepare membrane material by copolymerization or blend method.Blending method is a character of improving membrane material by complementarity between the composition polymer and cooperative effect, regulates and the controlling diaphragm performance by the compatibility difference of forming between polymer.At present, blend method mainly is by being blended into the hydrophily that the high polymer that has strong polar hydrophilic group improves pvdf membrane, but this method is improved the hydrophilic reduction that can cause the pvdf membrane mechanical strength simultaneously of pvdf membrane material sneaking into described high polymer, and is not ideal enough to the modification of pvdf membrane material.People such as Li Yanxiang (Li Yanxiang etc., a kind of preparation and performance [J] that contains the high molecule liquid crystal milipore filter. membrane science and technology .2000.10 (5) .27-31.) blend film of a kind of nematic high molecule liquid crystal and polysulfones disclosed.This blend film is (80 ℃) preparation at high temperature, is greater than 90% milipore filter to the bovine serum albumin(BSA) rejection.The described film forming condition of the document is too high to temperature requirement, and membrane flux improves and not obvious, and does not relate to the influence to the film mechanical strength of sneaking into of liquid crystal.
Summary of the invention
At the deficiencies in the prior art, the technical problem that quasi-solution of the present invention is determined is that a kind of Kynoar/liquid crystal blending microporous membrane and preparation method thereof is provided.This microporous barrier also has advantages such as mechanical strength height, good hydrophilic property and difficult pollution on the basis that keeps the intrinsic advantage of pvdf membrane; This microporous barrier preparation method technology is simple, does not need new equipment, does not pollute, and is suitable for industrializing implementation.
The technical scheme that the present invention solves described microporous membrane technology problem is: design a kind of Kynoar/liquid crystal blending microporous membrane, this microporous barrier mass percent (wt) % consists of:
Kynoar 10-30;
Macromolecule lysotropic liquid crystal 0.4-4;
Organic solvent, 56-88.6;
Additive 1-10,
Described macromolecule lysotropic liquid crystal is meant that cyanethyl cellulose or cyanoethyl ethyl cellulose are at N, dinethylformamide, N, N-dimethylacetylamide, N, in N-dimethyl sulfoxide (DMSO), glacial acetic acid or the acrylic acid, the lysotropic liquid crystal that more than critical concentration, forms greater than the formation liquid crystal; Described organic solvent is N, dinethylformamide, N, N-dimethylacetylamide, N, the mixed liquor of one or more arbitrary proportions in N-dimethyl sulfoxide (DMSO) and the N-methyl pyrrolidone; Described additive is the mixed liquor of one or more arbitrary proportions in anhydrous Lithium chloride, polyvinylpyrrolidone, sodium nitrate and the polyethylene glycol.
The technical scheme that the present invention solves described preparation method's technical problem is: the preparation method who designs a kind of Kynoar/liquid crystal blending microporous membrane, this preparation method adopts mass percent (wt) % of Kynoar/liquid crystal blending microporous membrane of the present invention to form, and realizes by following steps:
(1). the N that cyanethyl cellulose or the cyanoethyl ethyl cellulose of 25-75 (wt) % is dissolved in 25-75 (wt) %, dinethylformamide, N, N-dimethylacetylamide, N, in N-dimethyl sulfoxide (DMSO), glacial acetic acid or the acrylic acid, at 50 ℃ of following constant temperature 12h, at room temperature leave standstill 72h then, form lysotropic liquid crystal;
(2). take by weighing the Kynoar of 10-30 (wt) %, the macromolecule lysotropic liquid crystal of 0.4-4 (wt) %, the organic solvent of 56-88.6 (wt) % and the additive of 1-10 (wt) % respectively by mass percent;
(3). join described organic solvent, Kynoar and additive in the there-necked flask successively, under 40-80 ℃, stir 4-12h with the speed of 200r/min, even to mixed liquor, the lysotropic liquid crystal that adds described ratio then, behind speed stirring 8-12h under 60-100 ℃, with 400-800r/min, 60 ℃ of following vacuum defoamations, make casting solution;
(4). use traditional handicraft method and apparatus spinning hollow-fibre membrane or striking flat sheet membrane, in coagulating bath, carry out solid-liquid (S/L) then and be separated, obtain Kynoar/liquid crystal blending microporous membrane; Described coagulating bath is water and N, dinethylformamide, and N, the N-dimethylacetylamide, N, more than one of a kind of or arbitrary proportion in the N-dimethyl sulfoxide (DMSO) mix the coagulating bath of gained according to the ratio of 90-50: 10-50;
(5). resulting Kynoar/liquid crystal blending microporous membrane soaks 3-24h in protection liquid, dry naturally under room temperature then, promptly makes Kynoar/liquid crystal blending microporous membrane of the present invention; Described protection liquid is the mixed aqueous solution of the lauryl sodium sulfate of the glycerine of 10-80 (wt) % and 1-10 (wt) %.
Compared with prior art, macromolecule lysotropic liquid crystal material component has been adopted in microporous barrier design of the present invention, the high molecule liquid crystal that adds makes the Polymer Solution viscosity descend, mobile better, simultaneously because the orientation characteristic of liquid crystal molecule, can under lower traction condition, obtain the higher degree of orientation, thereby can avoid film when super drawing, to produce stress sustaining damage, thereby obtain the film of high strength, high-modulus.Combination properties such as prepared Kynoar/liquid crystal blending microporous membrane resistance tocrocking, service life and intensity are good.Microporous barrier preparation method of the present invention has adopted the high polymer that has strong polarity hydrophilic radical to prepare the macromolecule lyotropic liquid crystal, and with proper proportion and PVDF blend, the preparation microporous barrier, technology is simple, do not need new equipment, and can improve the mechanical strength and the hydrophily of film simultaneously, and reduce the film cost, be suitable for suitability for industrialized production.
The specific embodiment
Further narrate the present invention below in conjunction with embodiment:
Kynoar/the liquid crystal blending microporous membrane (hereinafter to be referred as microporous barrier or film) of the present invention's design, its mass percent (wt) % consists of:
Kynoar 10-30;
Macromolecule lysotropic liquid crystal 0.4-4;
Organic solvent, 56-88.6;
Additive 1-10,
Described macromolecule lysotropic liquid crystal is meant that cyanethyl cellulose or cyanoethyl ethyl cellulose are dissolved in N according to the ratio of 25-75 (wt) % and 25-75 (wt) %, dinethylformamide, N, N-dimethylacetylamide, N, in N-dimethyl sulfoxide (DMSO), glacial acetic acid or the acrylic acid, the lysotropic liquid crystal that more than critical concentration, forms greater than the formation liquid crystal; Described organic solvent is N, dinethylformamide, N, N-dimethylacetylamide, N, the mixed liquor of one or more arbitrary proportions in N-dimethyl sulfoxide (DMSO) and the N-methyl pyrrolidone; Described additive is the mixed liquor of one or more arbitrary proportions in anhydrous Lithium chloride, polyvinylpyrrolidone, sodium nitrate and the polyethylene glycol.
The present invention has designed the preparation method of Kynoar/liquid crystal blending microporous membrane simultaneously, and this preparation method adopts mass percent (wt) % of microporous barrier of the present invention to form, and realizes by following steps:
1. the N that cyanethyl cellulose or the cyanoethyl ethyl cellulose of 25-75 (wt) % is dissolved in 25-75 (wt) %, dinethylformamide, N, N-dimethylacetylamide, N, in N-dimethyl sulfoxide (DMSO), glacial acetic acid or the acrylic acid, at 50 ℃ of constant temperature 12h, at room temperature leave standstill 72h then, form lysotropic liquid crystal;
2. take by weighing the Kynoar of 10-30 (wt) %, the macromolecule lysotropic liquid crystal of 0.4-4 (wt) %, the organic solvent of 56-88.6 (wt) % and the additive of 1-10 (wt) % respectively by mass percent;
3. join described organic solvent, Kynoar, additive in the there-necked flask successively, under 40-80 ℃, stir 4-12h with the speed of 200r/min, even to mixed liquor, the lysotropic liquid crystal that adds described ratio then, behind speed stirring 8-12h under 60-100 ℃, with 400-800r/min, 60 ℃ of following vacuum defoamations, make casting solution;
4. use traditional handicraft method and apparatus spinning hollow-fibre membrane or striking flat sheet membrane, in coagulating bath, carry out solid-liquid (S/L) then and be separated, make Kynoar/liquid crystal blending microporous membrane; Described coagulating bath is the water of 50-90 (wt) % and the N of 50-10 (wt) %, dinethylformamide, N, N-dimethylacetylamide and N, the coagulating bath of one or more arbitrary proportion mixing gained in the N-dimethyl sulfoxide (DMSO);
5. prepared Kynoar/liquid crystal blending microporous membrane soaks 3-24h in protection liquid, dry naturally under room temperature then, promptly gets Kynoar/liquid crystal blending microporous membrane of the present invention; Described protection liquid is the mixed solution that the water of the lauryl sodium sulfate of the glycerine of 10-80 (wt) % and 1-10 (wt) % and surplus is formed.
Preparation method of the present invention is different with the liquid crystal film preparation method of prior art, when the liquid crystal film of prior art carries out the exchange process of solvent and water in coagulating bath, can break the orientations of liquid crystal molecule, has reduced the mechanical strength of liquid crystal film; Among the preparation method of microporous barrier of the present invention, added lyotropic liquid crystal in the casting solution as blend components.Promote the even dispersion of liquid crystal component in casting solution by high-speed stirred.In coagulating bath, carry out the coagulating bath of S/L when being separated film forming and adopt water and N, dinethylformamide, N, N-dimethylacetylamide, N, the N-dimethyl sulfoxide (DMSO), in glacial acetic acid and the acrylic acid one or more mix the coagulating bath of gained according to the ratio of 10/90-50/50, organic solvent and water in the casting solution are slowly exchanged, avoided when solvent and water exchange, because the rapid exchange of solvent and water destroys the orientation texture of liquid crystal, better preserve the orientations of liquid crystal molecule in PVDF, thereby kept the mechanical strength of liquid crystal film.Because the liquid crystal molecule of being sneaked into contains strong polarity hydrophilic radical, and the mechanical strength of pvdf membrane and water flux significantly improve after the modification, the anti-protein-contamination performance also makes moderate progress simultaneously.
The present invention adds in the PVDF casting solution that macromolecule is molten to cause (property) liquid crystal (abbreviation liquid crystal), make liquid crystal molecule orientations in PVDF by stretching, and under the synergy of the hydrophilic radical of liquid crystal molecule, improved the structure of pvdf membrane, hydrophilicity and mechanical strength, can effectively solve existing pvdf membrane at oil/water, pollution problem in the Separation of Proteins process, the water flux and the rejection of film have been improved, the cleaning frequency and the service life of film have been prolonged, improve the mechanical strength of film, improve voltage endurance capability, make the operation that film can be steady in a long-term, reduced the production and the use cost of film.Test shows that the hot strength of microporous barrier of the present invention can reach 13.40Mpa, and pure water flux can reach 480-800L/m
2H can reach more than 99% the rejection of ovalbumin (molecular weight 45000).
The present invention does not address part and is applicable to prior art.
Provide specific embodiments of the invention below.These embodiment further understand the present invention not limit claim of the present invention specifically.
Embodiment 1
1. the cyanethyl cellulose with 45 (wt) % is dissolved in the glacial acetic acid of 55 (wt) %, at 50 ℃ of constant temperature 12h, at room temperature leaves standstill 72h then, forms lysotropic liquid crystal;
2. take by weighing Kynoar respectively by mass percent: 15 (wt) %; Macromolecule lysotropic liquid crystal: 0.4 (wt) %; N, dinethylformamide: 79.6 (wt) %; Anhydrous Lithium chloride: 5 (wt) %;
3. with organic solvent, PVDF, additive joins in the there-necked flask successively, under 60 ℃, stir 6h with the speed of 200r/min, even to mixed liquor, the lysotropic liquid crystal that adds described ratio then, behind speed stirring 8h,, make casting solution 60 ℃ of following vacuum defoamations under 80 ℃, with 600r/min;
4. use traditional handicraft method and apparatus spinning hollow-fibre membrane, in coagulating bath, carry out solid-liquid (S/L) then and be separated, make Kynoar/liquid crystal blending microporous membrane; Described coagulating bath was water and N, and dinethylformamide mixes the coagulating bath of gained according to 50: 50 ratio;
5. prepared microporous barrier soaks 12h in the mixed aqueous solution of the lauryl sodium sulfate of glycerine and 1 (wt) % of 60 (wt) %, dry naturally under room temperature then, promptly makes Kynoar/liquid crystal blending microporous membrane of the present invention.
After measured, the prepared microporous barrier pure water flux of present embodiment (0.1MPa, 25 ℃ of following mensuration, down together) is by the 16L/m before the modification
2H brings up to the 521L/m after the modification
2Before by modification 81 ° of h, the contact angle of film are reduced to 68 ° after the modification, have obviously improved the hydrophily of film; Rejection to ovalbumin (molecular weight 45000) reaches 99.46%; The 1.82MPa of tensile break strength before by modification brought up to the 12.95MPa after the modification, and mechanical strength significantly increases.
Embodiment 2
1. the cyanethyl cellulose with 37.5 (wt) % is dissolved in the acrylic acid of 62.5 (wt) %, at 50 ℃ of constant temperature 12h, at room temperature leaves standstill 72h then, forms lysotropic liquid crystal;
2. take by weighing Kynoar respectively by mass percent: 10 (wt) %; Macromolecule lysotropic liquid crystal: 0.4 (wt) %; N, N-dimethylacetylamide: 79.6 (wt) %; Anhydrous Lithium chloride: 10 (wt) %;
3. with organic solvent, PVDF, additive joins in the there-necked flask successively, under 60 ℃, stir 4h with the speed of 200r/min, even to mixed liquor, the lysotropic liquid crystal that adds described ratio then, behind speed stirring 8h,, make casting solution 60 ℃ of following vacuum defoamations under 80 ℃, with 400r/min;
4. use traditional handicraft method and apparatus spinning hollow-fibre membrane, in coagulating bath, carry out solid-liquid (S/L) then and be separated, make Kynoar/liquid crystal blending microporous membrane; Described coagulating bath was water and N, and the N-dimethylacetylamide mixes the coagulating bath of gained according to 90: 10 ratio;
5. prepared microporous barrier soaks 24h in the mixed aqueous solution of the lauryl sodium sulfate of glycerine and 5 (wt) % of 20 (wt) %, dry naturally under room temperature then, promptly makes microporous barrier of the present invention.
After measured: the prepared microporous barrier pure water flux of present embodiment (0.1MPa, 25 ℃ of following mensuration) is by the 16L/m before the modification
2H brings up to the 530L/m after the modification
2H; The contact angle of film 81 ° before by modification are reduced to 68 ° after the modification; Rejection to ovalbumin (molecular weight 45000) reaches 98.83%, and tensile break strength has been brought up to 7.28MPa by 1.82MPa;
Embodiment 3
1. the cyanethyl cellulose of 28 (wt) % is dissolved in the N of 72 (wt) %, in the dinethylformamide,, at room temperature leaves standstill 72h then, form lysotropic liquid crystal at 50 ℃ of constant temperature 12h;
2. take by weighing Kynoar respectively by mass percent: 30 (wt) %; Macromolecule lysotropic liquid crystal: 0.4 (wt) %; N, N-dimethyl sulfoxide (DMSO): 59.6 (wt) %; Anhydrous Lithium chloride: 3 (wt) %, Macrogol 600: 7 (wt) %;
3. with organic solvent, PVDF, additive joins in the there-necked flask successively, under 80 ℃, stir 12h with the speed of 200r/min, even to mixed liquor, the lysotropic liquid crystal that adds described ratio then, behind speed stirring 12h,, make casting solution 60 ℃ of following vacuum defoamations under 80 ℃, with 800r/min;
4. use traditional handicraft method and apparatus spinning hollow-fibre membrane, in coagulating bath, carry out solid-liquid (S/L) then and be separated, make Kynoar/liquid crystal blending microporous membrane; Described coagulating bath was water and N, and the N-dimethyl sulfoxide (DMSO) mixes the coagulating bath of gained according to 80: 20 ratio;
5. prepared microporous barrier soaks 24h in the mixed aqueous solution of the lauryl sodium sulfate of glycerine and 10 (wt) % of 60 (wt) %, dry naturally under room temperature then, promptly makes microporous barrier of the present invention.
After measured: the prepared microporous barrier pure water flux of present embodiment (0.1MPa, 25 ℃ of mensuration) is by the 16L/m before the modification
2H brings up to the 503L/m after the modification
2H; The contact angle of film 81 ° before by modification are reduced to 67 ° after the modification; Rejection to ovalbumin (molecular weight 45000) reaches 96.45%, and its tensile break strength has been brought up to 13.48MPa by 1.82MPa.
Embodiment 4
1. the cyanethyl cellulose of 36 (wt) % is dissolved in the N of 64 (wt) %, in the N-dimethylacetylamide,, at room temperature leaves standstill 72h then, form lysotropic liquid crystal at 50 ℃ of constant temperature 12h;
2. take by weighing Kynoar respectively by mass percent: 20 (wt) %; Macromolecule lysotropic liquid crystal: 0.4 (wt) %; N, N-dimethylacetylamide: 37.3 (wt) %; N, N-dimethyl sulfoxide (DMSO): 37.3 (wt) %; Macrogol 600: 5 (wt) %;
3. with organic solvent, PVDF, additive joins in the there-necked flask successively, under 40 ℃, stir 8h with the speed of 200r/min, even to mixed liquor, the lysotropic liquid crystal that adds described ratio then, behind speed stirring 12h,, make casting solution 60 ℃ of following vacuum defoamations under 60 ℃, with 600r/min;
4. use traditional handicraft method and apparatus striking flat sheet membrane, in coagulating bath, carry out solid-liquid (S/L) then and be separated, make Kynoar/liquid crystal blending microporous membrane; Described coagulating bath was water and N, and N-dimethylacetylamide and N, N-dimethyl sulfoxide (DMSO) mix the coagulating bath of gained according to 70: 15: 15 ratio;
5. prepared microporous barrier soaks 24h in the mixed aqueous solution of the lauryl sodium sulfate of glycerine and 5 (wt) % of 40 (wt) %, dry naturally under room temperature then, promptly makes microporous barrier of the present invention.
After measured: the prepared microporous barrier pure water flux of present embodiment (0.1MPa25 ℃ of mensuration) is by the 16L/m before the modification
2H brings up to the 480L/m after the modification
2H; The contact angle of film 81 ° before by modification are reduced to 68 ° after the modification; Rejection to ovalbumin (molecular weight 45000) reaches 95.54%, and its tensile break strength has been brought up to 11.23MPa by 1.82MPa.
Embodiment 5
1. the cyanethyl cellulose of 20 (wt) % is dissolved in the N of 80 (wt) %, in the N-dimethyl sulfoxide (DMSO),, at room temperature leaves standstill 72h then, form lysotropic liquid crystal at 50 ℃ of constant temperature 12h;
2. take by weighing Kynoar respectively by mass percent: 15 (wt) %; Macromolecule lysotropic liquid crystal: 0.4 (wt) %; N, dinethylformamide: 76.6 (wt) %; Macrogol 600: 5 (wt) %; Sodium nitrate: 3 (wt) %;
3. with embodiment 1 step 3;
4. use traditional handicraft method and apparatus striking flat sheet membrane, in coagulating bath, carry out solid-liquid (S/L) then and be separated, make Kynoar/liquid crystal blending microporous membrane; Described coagulating bath was water and N, and dinethylformamide mixes the coagulating bath of gained according to 60: 40 ratio;
5. with embodiment 1 step 5.
After measured: the prepared microporous barrier pure water flux of present embodiment (0.1MPa, 25 ℃ of following mensuration) is by the 16L/m before the modification
2H brings up to the 498L/m after the modification
2H; The contact angle of film 81 ° before by modification are reduced to 68 ° after the modification; Rejection to ovalbumin (molecular weight 45000) reaches 99.18%, and its tensile break strength has been brought up to 10.13MPa.
Embodiment 6
1. with embodiment 1 step 1;
2. take by weighing Kynoar respectively by mass percent: 15 (wt) %; Macromolecule lysotropic liquid crystal: 4 (wt) %; N, dinethylformamide: 76 (wt) %; Polyvinylpyrrolidone: 5 (wt) %;
3. with organic solvent, PVDF, additive joins in the there-necked flask successively, under 60 ℃, stir 8h with the speed of 200r/min, even to mixed liquor, the lysotropic liquid crystal that adds described ratio then, behind speed stirring 12h,, make casting solution 60 ℃ of following vacuum defoamations under 100 ℃, with 800r/min;
4. with embodiment 1 step 4;
5. with embodiment 2 steps 5.
After measured: the prepared microporous barrier pure water flux of present embodiment (0.1MPa, 25 ℃ of mensuration) is by the 16L/m before the modification
2H brings up to the 800L/m after the modification
2H; The contact angle of film 81 ° before by modification are reduced to 53 ° after the modification; Rejection to 2g/L ovalbumin (molecular weight 45000) reaches 75.38%, and its tensile break strength has been brought up to 3.54MPa.
Embodiment 7
1. with embodiment 1 step 1;
2. take by weighing Kynoar respectively by mass percent: 15 (wt) %; Macromolecule lysotropic liquid crystal: 2 (wt) %; N, dinethylformamide: 78 (wt) %; Macrogol 600: 5 (wt) %;
3. with embodiment 6 steps 3;
4. use traditional handicraft method and apparatus striking flat sheet membrane, in coagulating bath, carry out solid-liquid (S/L) then and be separated, make Kynoar/liquid crystal blending microporous membrane; Described coagulating bath was water and N, and dinethylformamide mixes the coagulating bath of gained according to 70: 30 ratio;
5. with embodiment 3 steps 5.
After measured: the prepared microporous barrier pure water flux of present embodiment (0.1MPa, 25 ℃ of mensuration) is by the 16L/m before the modification
2H brings up to the 740L/m after the modification
2H; The contact angle of film 81 ° before by modification are reduced to 58 ° after the modification; Rejection to 2g/L ovalbumin (molecular weight 45000) reaches 83.83%, and its tensile break strength has been brought up to 4.21MPa.
Embodiment 8
1. the cyanoethyl ethyl cellulose of 42 (wt) % is sneaked in the glacial acetic acid of 58 (wt) %,, at room temperature leave standstill 72h then, form lysotropic liquid crystal at 50 ℃ of constant temperature 12h;
2. take by weighing Kynoar respectively by mass percent: 15 (wt) %; Macromolecule lysotropic liquid crystal: 0.4 (wt) %; N, N-dimethyl formamide: 79.6 (wt) %; Sodium nitrate: 5 (wt) %;
3. with embodiment 1 step 3;
4. use traditional handicraft method and apparatus striking flat sheet membrane, in coagulating bath, carry out solid-liquid (S/L) then and be separated, make Kynoar/liquid crystal blending microporous membrane; Described coagulating bath was water and N, and dinethylformamide mixes the coagulating bath of gained according to 80: 20 ratio;
5. with embodiment 4 steps 5.
After measured: the prepared microporous barrier pure water flux of present embodiment (0.1MPa, 25 ℃ of mensuration) is by the 16L/m before the modification
2H brings up to the 540L/m after the modification
2H; The contact angle of film 81 ° before by modification are reduced to 68 ° after the modification; Rejection to 2g/L ovalbumin (molecular weight 45000) reaches 96.77%, and its tensile break strength has been brought up to 10.02MPa.
Embodiment 9
1. with embodiment 8 steps 1;
2. take by weighing Kynoar by mass percent: 15 (wt) %; Macromolecule lysotropic liquid crystal: 0.4 (wt) %; N, dinethylformamide: 79.6 (wt) %; Anhydrous Lithium chloride: 3.75 (wt) %; Polyvinylpyrrolidone: 1.75 (wt) %;
3. with embodiment 1 step 3;
4. with embodiment 8 steps 4;
5. with embodiment 4 steps 5;
After measured: the prepared microporous barrier pure water flux of present embodiment (0.1MPa, 25 ℃ of mensuration) is by the 16L/m before the modification
2H brings up to the 780L/m after the modification
2H; The contact angle of film 81 ° before by modification are reduced to 60 ° after the modification; Rejection to 2g/L ovalbumin (molecular weight 45000) reaches 86.77%, and its tensile break strength has been brought up to 5.73MPa.
Claims (2)
1. Kynoar/liquid crystal blending microporous membrane, this microporous barrier mass percent (wt) % consists of:
Kynoar 10-30;
Macromolecule lysotropic liquid crystal 0.4-4;
Organic solvent, 56-88.6;
Additive 1-10,
Described macromolecule lysotropic liquid crystal is meant that cyanethyl cellulose or cyanoethyl ethyl cellulose are dissolved in N according to 25-75 (wt) % and 25-75 (wt) %, dinethylformamide, N, N-dimethylacetylamide, N, in N-dimethyl sulfoxide (DMSO), glacial acetic acid or the acrylic acid, the lysotropic liquid crystal that more than critical concentration, forms greater than the formation liquid crystal; Described organic solvent is N, dinethylformamide, N, N-dimethylacetylamide, N, the mixed liquor of one or more arbitrary proportions in N-dimethyl sulfoxide (DMSO) and the N-methyl pyrrolidone; Described additive is the mixed liquor of one or more arbitrary proportions in anhydrous Lithium chloride, polyvinylpyrrolidone, sodium nitrate and the polyethylene glycol.
2. the preparation method of a Kynoar/liquid crystal blending microporous membrane, this preparation method adopt mass percent (wt) % of the described Kynoar/liquid crystal blending microporous membrane of claim 1 to form, and realize by following steps:
(1). the N that cyanethyl cellulose or the cyanoethyl ethyl cellulose of 25-75 (wt) % is dissolved in 25-75 (wt) %, dinethylformamide, N, N-dimethylacetylamide, N, in N-dimethyl sulfoxide (DMSO), glacial acetic acid or the acrylic acid, at 50 ℃ of following constant temperature 12h, at room temperature leave standstill 72h then, form lysotropic liquid crystal;
(2). take by weighing the Kynoar of 10-30 (wt) %, the macromolecule lysotropic liquid crystal of 0.4-4 (wt) %, the organic solvent of 56-88.6 (wt) % and the additive of 1-10 (wt) % respectively by mass percent;
(3). join described organic solvent, Kynoar, additive in the there-necked flask successively, under 40-80 ℃, stir 4-12h with the speed of 200r/min, even to mixed liquor, the lysotropic liquid crystal that adds described ratio then, behind speed stirring 8-12h under 60-100 ℃, with 400-800r/min, 60 ℃ of following vacuum defoamations, make casting solution;
(4). use traditional handicraft method and apparatus spinning hollow-fibre membrane or striking flat sheet membrane, in coagulating bath, carry out solid-liquid (S/L) then and be separated, obtain Kynoar/liquid crystal blending microporous membrane; Described coagulating bath is water and N, dinethylformamide, and N, the N-dimethylacetylamide, N, one or more in the N-dimethyl sulfoxide (DMSO) mix the coagulating bath of gained according to the ratio of 90-50: 10-50;
(5). resulting Kynoar/liquid crystal blending microporous membrane soaks 3-24h in protection liquid, dry naturally under room temperature then, promptly makes Kynoar/liquid crystal blending microporous membrane of the present invention; Described protection liquid is the mixed aqueous solution of the lauryl sodium sulfate of the glycerine of 10-80 (wt) % and 1-10 (wt) %.
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| CN102008903A (en) * | 2010-10-09 | 2011-04-13 | 天津工业大学 | Lyotropic liquid crystal-blended microporous film and preparation method thereof |
| CN103242660B (en) * | 2013-05-27 | 2015-12-23 | 刘江萍 | A kind of method preparing high dielectric thin film |
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| US4241128A (en) * | 1979-03-20 | 1980-12-23 | Bell Telephone Laboratories, Incorporated | Production of piezoelectric PVDF films |
| CN1350048A (en) * | 2000-10-23 | 2002-05-22 | 阿托费纳化学股份有限公司 | Narrow-arranged poly-phosphinodifluoro-ethylene reversible and electrocontrollable transparent film, its making mehtod, product and composition therefrom |
| KR20090030825A (en) * | 2007-09-21 | 2009-03-25 | 경희대학교 산학협력단 | METHOD FOR PRODUCING POLY(VINYLIDENE FLUORIDE) FILM WITH HIGH beta-TYPE CRYSTAL STRUCTURE |
| JP2009104967A (en) * | 2007-10-25 | 2009-05-14 | Nitto Denko Corp | Method for manufacturing polymer electrolyte membrane, polymer electrolyte membrane and membrane-electrode assembly, and polymer electrolyte type fuel cell |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4241128A (en) * | 1979-03-20 | 1980-12-23 | Bell Telephone Laboratories, Incorporated | Production of piezoelectric PVDF films |
| CN1350048A (en) * | 2000-10-23 | 2002-05-22 | 阿托费纳化学股份有限公司 | Narrow-arranged poly-phosphinodifluoro-ethylene reversible and electrocontrollable transparent film, its making mehtod, product and composition therefrom |
| KR20090030825A (en) * | 2007-09-21 | 2009-03-25 | 경희대학교 산학협력단 | METHOD FOR PRODUCING POLY(VINYLIDENE FLUORIDE) FILM WITH HIGH beta-TYPE CRYSTAL STRUCTURE |
| JP2009104967A (en) * | 2007-10-25 | 2009-05-14 | Nitto Denko Corp | Method for manufacturing polymer electrolyte membrane, polymer electrolyte membrane and membrane-electrode assembly, and polymer electrolyte type fuel cell |
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