CN111001299B - Aperture asymmetric diaphragm, preparation method and application in seawater desalination - Google Patents
Aperture asymmetric diaphragm, preparation method and application in seawater desalination Download PDFInfo
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- CN111001299B CN111001299B CN201911401649.3A CN201911401649A CN111001299B CN 111001299 B CN111001299 B CN 111001299B CN 201911401649 A CN201911401649 A CN 201911401649A CN 111001299 B CN111001299 B CN 111001299B
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
- B01D61/02—Reverse osmosis; Hyperfiltration ; Nanofiltration
- B01D61/025—Reverse osmosis; Hyperfiltration
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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
- B01D67/002—Organic membrane manufacture from melts
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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
- B01D67/0081—After-treatment of organic or inorganic membranes
- B01D67/0083—Thermal after-treatment
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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
- B01D67/0081—After-treatment of organic or inorganic membranes
- B01D67/0086—Mechanical after-treatment
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- 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
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- 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
- B01D71/26—Polyalkenes
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
- C02F1/441—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by reverse osmosis
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2323/00—Details relating to membrane preparation
- B01D2323/50—Control of the membrane preparation process
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2325/00—Details relating to properties of membranes
- B01D2325/02—Details relating to pores or porosity of the membranes
- B01D2325/022—Asymmetric membranes
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
- C02F2103/08—Seawater, e.g. for desalination
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A20/00—Water conservation; Efficient water supply; Efficient water use
- Y02A20/124—Water desalination
- Y02A20/131—Reverse-osmosis
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Abstract
The invention belongs to the technical field of lithium battery diaphragms, and particularly relates to a diaphragm with an asymmetric aperture, a preparation method and application in seawater desalination. Wherein the asymmetric-aperture membrane comprises: a diaphragm distributed with a multi-layer micropore structure; wherein the pore diameter of the microporous structure on the upper surface layer and the lower surface layer of the diaphragm is not equal to each other. When seawater passes through the membrane, the microporous structure of the upper surface layer of the membrane is suitable for water molecules and dissolved oxygen to pass smoothly, but can cut off impurities, bacteria and macromolecular salt substances in the seawater, drinkable fresh water is obtained on the lower surface layer of the membrane, and seawater desalination is realized.
Description
Technical Field
The invention belongs to the technical field of lithium battery diaphragms, and particularly relates to a diaphragm with an asymmetric aperture, a preparation method and application in seawater desalination.
Background
Fresh water resources in China are increasingly in short supply, and per capita water resources only account for one fourth of the world level. But the seawater resources in China are very rich, so the seawater desalination technology has wide prospect.
The current technical situation is as follows: in the aspect of materials, polysulfone gradually replaces early cellulose materials due to the characteristics of stable chemical structure, higher heat resistance, good mechanical strength, easiness in processing and the like, and becomes a research subject in recent years that a hydrophobic macroporous polysulfone porous skin layer is adopted to prepare a high-water-flux composite membrane, and a polyolefin diaphragm is not used as a seawater desalination filtration membrane at present.
Disclosure of Invention
The invention aims to provide a diaphragm with asymmetric aperture, a preparation method and application in seawater desalination.
In order to solve the above technical problem, the present invention provides a membrane with an asymmetric pore size, comprising: a diaphragm distributed with a multi-layer micropore structure; wherein the pore diameter of the microporous structure on the upper surface layer and the lower surface layer of the diaphragm is not equal to each other.
Furthermore, the pore diameters of the microporous structures of the upper surface layer, the middle layer and the lower surface layer of the diaphragm are sequentially 100-200nm, 70-100nm and 10-40 nm.
Further, the thickness ratio of the upper surface layer, the middle layer and the lower surface layer of the diaphragm is 1/4: 1/2: 1/4.
In a second aspect, the present invention also provides a method for preparing a membrane with an asymmetric pore size, comprising: blending and extruding, namely melting and extruding the raw materials to obtain a melt; cooling the cast sheet, namely, obtaining a gel sheet by the melt through sheet casting; asynchronous biaxial stretching, namely stretching the gel sheet to obtain a stretched film; extracting, namely washing the stretched membrane by an extracting agent to remove paraffin oil to obtain a microporous membrane; heat setting, namely controlling the processing temperature difference of the upper surface and the lower surface of the microporous diaphragm so as to ensure that the pore diameters of the microporous structures of the upper surface and the lower surface of the microporous diaphragm are different; and rolling and slitting to obtain the multilayer microporous diaphragm with asymmetric aperture on two sides.
Further, the raw materials include: 10-40% of mixed polyethylene resin and 60-90% of paraffin oil; wherein the hybrid polyethylene resin comprises: the mass ratio is 5: 5-95 parts of ultrahigh molecular weight polyethylene resin and high density polyethylene resin.
Further, the asynchronous biaxial stretching includes: longitudinal stretching and transverse stretching; wherein the two times of stretching temperature is 50-130 ℃; the stretching magnification is 5-15 times.
Further, the thickness of the stretched film is 5 to 60 μm.
Further, the processing temperature of the upper surface layer of the microporous membrane is 100-120 ℃; the processing temperature of the lower surface layer of the microporous diaphragm is 130-150 ℃.
In a third aspect, the invention also provides an application of the membrane with the asymmetric pore diameter as a reverse osmosis membrane for seawater desalination.
The invention has the advantages that the pore diameter of the membrane with asymmetric pore diameter and the preparation method thereof, and the application of the membrane in seawater desalination lead the pore structures on the upper surface layer and the lower surface layer of the membrane to have unequal pore diameters; when seawater passes through the membrane, the macroporous structure of the upper surface layer of the membrane cuts off macromolecular impurities and bacteria in the seawater, the micropores of the middle layer of the membrane mainly filter calcium and magnesium salt substances, and the micropores of the lower surface layer of the membrane mainly ensure that oxygen and water molecules for removing calcium and magnesium in the seawater smoothly pass through to obtain drinkable fresh water, so that seawater desalination is realized.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
Fig. 1 is a flow chart of a process for preparing the asymmetric pore size membrane of the present invention.
Detailed Description
To make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is apparent that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
The aperture asymmetric membrane of embodiment 1 includes: a diaphragm distributed with a multi-layer micropore structure; wherein the pore diameter of the microporous structure on the upper surface layer and the lower surface layer of the diaphragm is not equal to each other.
Optionally, the pore diameters of the microporous structures of the upper surface layer 1, the middle layer 2 and the lower surface layer 3 of the diaphragm are sequentially 100-200nm, 70-100nm and 10-40 nm. Optionally, the pore diameters of the microporous structures of the upper surface layer, the middle layer and the lower surface layer of the diaphragm are 140nm, 80nm and 25nm in sequence.
Optionally, the thickness ratio of the upper surface layer, the middle layer and the lower surface layer of the diaphragm is 1/4: 1/2: 1/4 the macroporous structure of the upper surface layer of the diaphragm separates the macromolecular impurities and bacteria in the seawater, the micropores of the middle layer of the diaphragm mainly filter the calcium and magnesium salt substances, and the micropores of the lower surface mainly ensure that the oxygen and the water molecules for removing the calcium and magnesium in the seawater smoothly pass through to obtain drinkable fresh water.
The pore diameter of the membrane with asymmetric pore diameter is unequal, so that the dense and small-pore-diameter microporous structures are distributed on the upper surface of the membrane, and the large-pore-diameter microporous structures are distributed on the lower surface of the membrane, when seawater passes through the membrane, the microporous structures on the upper surface layer of the membrane are suitable for water molecules and dissolved oxygen to pass through smoothly, but can separate impurities, bacteria and macromolecular salt substances (the diameter is more than 10nm) in the seawater, drinkable fresh water is obtained on the lower surface layer of the membrane, and seawater desalination is realized.
Example 2
Referring to fig. 1, on the basis of embodiment 1, embodiment 2 further provides a method for preparing a membrane with an asymmetric pore size, including: blending and extruding, namely melting and extruding the raw materials to obtain a melt; cooling the cast sheet, namely, obtaining a gel sheet by the melt through sheet casting; asynchronous biaxial stretching, namely stretching the gel sheet to obtain a stretched film; extracting, namely washing the stretched membrane by an extracting agent to remove paraffin oil to obtain a microporous membrane; heat setting, namely controlling the processing temperature difference of the upper surface and the lower surface of the microporous diaphragm so as to ensure that the pore diameters of the microporous structures of the upper surface and the lower surface of the microporous diaphragm are different; and rolling and slitting to obtain the multilayer microporous diaphragm with asymmetric apertures on two sides (namely the diaphragm with asymmetric apertures).
As an alternative to blending extrusion.
The raw materials are melted and extruded by a double-screw co-rotating extruder (the temperature of the extruder is controlled to be 190 ℃ and 250 ℃), and a melt with the temperature of 190 ℃ and 250 ℃ is obtained. Wherein the raw materials comprise: 10-40% of mixed polyethylene resin and 60-90% of paraffin oil; wherein the hybrid polyethylene resin comprises: the mass ratio is 5: 5-95 parts of ultrahigh molecular weight polyethylene resin and high density polyethylene resin. And the ultra-high molecular weight polyethylene resin has an average molecular weight of 1 x 106-4*106The weight average molecular weight of the high density polyethylene resin was 5 x 105-8*105. The paraffin oil can be liquid, solid or a mixture of the two, wherein the molecular weight of the paraffin oil is 300-1500.
Optionally, the raw materials include: 20 mass percent of mixed polyethylene resin and 80 mass percent of paraffin oil; wherein the hybrid polyethylene resin comprises: the mass ratio is 5: 30 parts of ultra-high molecular weight polyethylene resin and high density polyethylene resin.
Optionally, the raw materials include: 30% of mixed polyethylene resin and 70% of paraffin oil; wherein the hybrid polyethylene resin comprises: the mass ratio is 5: 50 of ultra-high molecular weight polyethylene resin and high density polyethylene resin.
Optionally, the raw materials include: 35% of mixed polyethylene resin and 65% of paraffin oil; wherein the hybrid polyethylene resin comprises: the mass ratio is 5: 80 of ultra-high molecular weight polyethylene resin and high density polyethylene resin.
The blending extrusion of the embodiment is to melt and extrude the ultra-high molecular weight polyethylene resin, the high density polyethylene resin and the paraffin oil to obtain a melt of 190-250 ℃, and the melt flows out of a die head, so that the strength and the extensibility of the diaphragm can be improved from raw materials.
Optionally, the cooling of the cast slab includes: the melt at the temperature of 190 ℃ and 250 ℃ passes through a casting sheet (the temperature is 10-60 ℃) to obtain a gel sheet at the temperature of 20-50 ℃.
Optionally, the asynchronous bidirectional stretching includes: the gel sheet is stretched longitudinally (MD) and Transversely (TD) at 50-130 deg.C for 5-15 times to obtain 5-60 μm stretched film, preferably 20-60 μm membrane, which has enough thickness and certain pressure to operate and ensure high mechanical strength without severe deformation.
Optionally, the extracting comprises: and (3) passing the stretched membrane through an extraction tank, washing and removing paraffin oil in the micropores of the membrane by using an extractant, and drying and removing the extractant to obtain the microporous membrane. Generally, the extractant is a chemical agent with good compatibility with paraffin oil, such as dichloromethane.
Optionally, the processing temperature of the upper surface layer of the microporous membrane is 100-120 ℃, preferably 110-115 ℃; the processing temperature of the lower surface layer of the microporous diaphragm is obtained to be 130-150 ℃, preferably 135-140 ℃, and the pore diameter of the microporous structure of the upper surface layer of the microporous diaphragm is obtained to be 100-200 nm; the pore diameter of the microporous structure of the middle layer is 70-100 nm; the pore diameter of the microporous structure of the lower surface layer is 10-40 nm. The normal condition heat setting can form 50-200nm micropores by stretching 1.2-2 times at the temperature of 100-125 ℃, the application utilizes the uniform high-temperature 130-150 ℃ hot air on the lower surface, and the micropores 50-200nm in the thickness of the lower surface 1/4 are closed to form new micropores 10-40nm, thereby forming the membrane with asymmetric pore diameter.
Optionally, the rolling and slitting comprises: winding the heat-set diaphragm by a winding machine at a speed of 30-90 m/min, and then slitting by a slitting machine at a speed of 100-200 m/min to obtain the diaphragms with different width specifications and asymmetric apertures;
example 3
On the basis of the embodiment 1 or 2, the embodiment 3 also provides an application of the membrane with the asymmetric pore size as a seawater desalination reverse osmosis membrane.
Specifically, the upper surface of the diaphragm is distributed with a compact microporous structure with small pore diameter, the lower surface of the diaphragm is distributed with a microporous structure with large pore diameter, when seawater passes through the diaphragm, the microporous structure of the upper surface layer of the diaphragm is suitable for water molecules and dissolved oxygen to pass through smoothly, but can cut off impurities, bacteria and macromolecular salt substances (the diameter is more than 10nm) in the seawater, drinkable fresh water is obtained on the lower surface layer of the diaphragm, and seawater desalination is realized.
Example 4
(1) Blending extrusion
Firstly, the mass ratio is 5: 30 parts of ultrahigh molecular weight polyethylene resin and high density polyethylene resin are mixed to form mixed polyethylene resin, then 25 parts of mixed polyethylene resin and 75 parts of paraffin oil are proportioned according to the mass portion, and the mixture is melted and extruded by a double-screw co-rotating extruder (the temperature of the extruder is controlled to be 200 ℃) to obtain melt of 200 ℃.
(2) Cooling of cast sheet
The gel sheet of 20 ℃ was prepared by the procedure of casting the melt of 200 ℃ at 10 ℃.
(3) Asynchronous biaxial tension
The gel sheet was successively stretched 5 times at a temperature of 100 ℃ after longitudinal stretching (MD) and transverse stretching (TD) to obtain a 15.7 μm stretched film.
(4) Extraction of
And (3) passing the stretched membrane through an extraction tank, washing and removing paraffin oil in the micropores of the membrane by using dichloromethane, and drying and removing dichloromethane to obtain the microporous membrane.
(5) Heat setting
Heat setting the diaphragm, wherein the processing temperature of the upper surface layer of the microporous diaphragm is 100 ℃; the processing temperature of the lower surface layer of the microporous diaphragm is 130 ℃.
(6) Rolling and slitting
And (3) winding the heat-set diaphragm by a winding machine at a speed of 60 m/min, and then slitting by a slitting machine at a speed of 150 m/min to obtain the diaphragms with different width specifications and asymmetric apertures.
Example 6
(1) Blending extrusion
Firstly, the mass ratio is 5: 45 parts of ultrahigh molecular weight polyethylene resin and high density polyethylene resin are mixed to form mixed polyethylene resin, then 25 parts of mixed polyethylene resin and 75 parts of paraffin oil are proportioned according to the mass portion, and the mixture is melted and extruded by a double-screw co-rotating extruder (the temperature of the extruder is controlled to be 200 ℃) to obtain melt of 200 ℃.
(2) Cooling of cast sheet
The melt at 200 ℃ was subjected to a sheet casting (temperature 20 ℃) procedure to prepare a gel sheet at 20 ℃.
(3) Asynchronous biaxial tension
The gel sheet was successively stretched 10 times at a temperature of 100 ℃ after longitudinal stretching (MD) and transverse stretching (TD) to obtain a 11.87 μm stretched film.
(4) Extraction of
And (3) passing the stretched membrane through an extraction tank, washing and removing paraffin oil in the micropores of the membrane by using dichloromethane, and drying and removing dichloromethane to obtain the microporous membrane.
(5) Heat setting
Heat setting the diaphragm, wherein the processing temperature of the upper surface layer of the microporous diaphragm is 120 ℃; the processing temperature of the lower surface layer of the microporous diaphragm is 150 ℃.
(6) Rolling and slitting
And winding the heat-set diaphragm by a winding machine at a speed of 90 m/min, and then slitting by a slitting machine at a speed of 150 m/min to obtain the diaphragms with different width specifications and asymmetric apertures.
Example 7
(1) Blending extrusion
Firstly, the mass ratio is 5: 75 parts of ultrahigh molecular weight polyethylene resin and high density polyethylene resin are mixed to form mixed polyethylene resin, then the mixed polyethylene resin with the mass part of 40% and paraffin oil with the mass part of 60% are proportioned, and the mixture is melted and extruded by a double-screw co-rotating extruder (the temperature of the extruder is controlled to be 210 ℃) to obtain melt with the temperature of 210 ℃.
(2) Cooling of cast sheet
The melt with the temperature of 210 ℃ is processed by a sheet casting process (the temperature is 10-60 ℃) to prepare a gel sheet with the temperature of 20-50 ℃.
(3) Asynchronous biaxial tension
The gel sheet was successively stretched 15 times at a temperature of 50 ℃ after longitudinal stretching (MD) and transverse stretching (TD) to obtain a 9.01 μm stretched film.
(4) Extraction of
And (3) passing the stretched membrane through an extraction tank, washing and removing paraffin oil in micropores of the membrane by using dichloromethane, and drying and removing dichloromethane to obtain the membrane.
(5) Heat setting
Heat setting the diaphragm, wherein the processing temperature of the upper surface layer of the microporous diaphragm is 110 ℃; the processing temperature of the lower surface layer of the microporous diaphragm is 140 ℃.
(6) Rolling and slitting
And winding the heat-set diaphragm by a winding machine at a speed of 80 m/min, and then slitting by a slitting machine at a speed of 200 m/min to obtain the diaphragms with different width specifications and asymmetric apertures.
Example 8
In this example 8, the membranes with asymmetric pore diameters prepared in examples 4 to 6 and the seawater desalination filtration membrane (polysulfone porous skin layer composite membrane) in the prior art were respectively tested, and the test results are shown in table 1.
TABLE 1 comparison of the properties of the membranes
In the context of table 1, the following,
salt rejection: removing the percentage of soluble impurity concentration from the inlet water of the system through a reverse osmosis membrane, wherein the desalination rate is (1-water production salinity/inlet water salinity) multiplied by 100%;
and (3) recovery rate: the percent of feed water converted to product water or permeate in the membrane system is expressed as recovery (product water flow/feed water flow) x 100%.
By combining examples 4-6 and comparative examples, it can be seen that the desalination rate and recovery rate of the asymmetric-pore-diameter membrane of the present invention are both higher than those of the prior art, and the operating pressure difference at both sides of the membrane is lower than that of the conventional art, mainly because the asymmetric-pore-diameter membrane can ensure that the seawater impurities are filtered by the macroporous structure with the thickness of 1/4 on the upper surface, the membrane micropores in the whole thickness direction are not blocked, and the membrane micropores with the thickness of 3/4 can be normally used.
In light of the foregoing description of the preferred embodiment of the present invention, many modifications and variations will be apparent to those skilled in the art without departing from the spirit and scope of the invention. The technical scope of the present invention is not limited to the content of the specification, and must be determined according to the scope of the claims.
Claims (1)
1. An application of a pore-diameter asymmetric membrane for seawater desalination as a reverse osmosis membrane for seawater desalination is characterized in that,
the asymmetric-aperture diaphragm for seawater desalination comprises:
a diaphragm distributed with a multi-layer micropore structure; wherein
The pore diameters of the microporous structures on the upper surface layer and the lower surface layer of the diaphragm are not equal;
the pore diameters of the microporous structures of the upper surface layer, the middle layer and the lower surface layer of the diaphragm are sequentially 100-200nm, 70-100nm and 10-40 nm;
the thickness ratio of the upper surface layer, the middle layer and the lower surface layer of the diaphragm is 1/4: 1/2: 1/4, respectively;
the raw materials of the pore-diameter asymmetric diaphragm for seawater desalination comprise: 10-40% of mixed polyethylene resin and 60-90% of wax oil; wherein
The hybrid polyethylene resin includes: the mass ratio is 5: 5-95 parts of ultrahigh molecular weight polyethylene resin and high density polyethylene resin.
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| CN112090294A (en) * | 2020-09-18 | 2020-12-18 | 江苏厚生新能源科技有限公司 | Asymmetric polyolefin porous membrane and raw material formula, preparation method and application thereof |
| CN112076633A (en) * | 2020-09-28 | 2020-12-15 | 江苏厚生新能源科技有限公司 | Reverse osmosis membrane and preparation method thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101253232A (en) * | 2005-09-16 | 2008-08-27 | 东燃化学株式会社 | Polyethylene microporous membrane, process for production thereof, and battery separator |
| CN107958981A (en) * | 2017-06-24 | 2018-04-24 | 湖南中锂新材料有限公司 | A kind of composite diaphragm and preparation method for lithium-ion-power cell |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101253232A (en) * | 2005-09-16 | 2008-08-27 | 东燃化学株式会社 | Polyethylene microporous membrane, process for production thereof, and battery separator |
| CN107958981A (en) * | 2017-06-24 | 2018-04-24 | 湖南中锂新材料有限公司 | A kind of composite diaphragm and preparation method for lithium-ion-power cell |
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