CN101780378B - Method for preparing fluoropolymer microporous films through using ion liquid as film preparation media - Google Patents
Method for preparing fluoropolymer microporous films through using ion liquid as film preparation media Download PDFInfo
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Abstract
The invention discloses a method for preparing fluoropolymer microporous films through using ion liquid as film preparation media, which comprises the following steps: (1) dissolving fluoropolymers in ion liquid under the heating condition to obtain a film preparation solution; (2), pressing the film preparation solution into a film after the film preparation solution is cooled into solid in liquid nitrogen; and (3) placing the pressed ion liquid/fluoropolymer thin film into an extracting agent, and removing the ion liquid through extraction to obtain the fluoropolymer microporous film. The invention adopts the ion liquid as the film preparation media, the ion liquid has low steam pressure, is hardly evaporated, and can be recovered for cyclic use, so the problems of toxicity and pollution caused by using volatile organic solvents in the traditional film preparation method are solved. The fluoropolymer microporous film prepared by the method of the invention has the advantages of high mechanical strength, good hole connectivity, high porosity and adjustable hole diameter, and can be used as a high-flux hyperfiltration or micro-filtration film.
Description
Technical field
The present invention relates to the preparation method of polymer microporous film, relating in particular to a kind of is the method that the system film medium prepares the fluoropolymer microporous barrier with the ionic liquid.
Background technology
Membrane separation technique is a kind of new and effective isolation technics, compare with traditional isolation technics, it has outstanding advantages such as separative efficiency height, energy consumption low (no phase transformation), environmental friendliness, is applicable to almost that petrochemical industry/chemical industry, food, pharmacy/medical treatment, dyestuff, natural materials extract and concentrate, the separating of the liquid in each field such as water purification and wastewater treatment, gas medium, purifying and resource reclaim.The core of membrane separation technique is a separation membrane material, includes organic polymeric membrane (being polymer film) and inoranic membrane two big classes, and wherein polymer film accounts for more than 95%.In numerous polymeric film material, the polymer microporous film that is used for ultrafiltration and micro-filtration is research and most widely used one big class film.Owing in application process, need stand the cleaning of strong oxidizing property, strong acid alkaline chemical, therefore need polymeric film material to have excellent chemical stability.
Fluoropolymer, a kind of as macromolecular material, owing to have many particular structure, thereby just show a lot of special nature, and such as: the polarizability that fluorine atom is lower, strong electronegativity, less van der Waals radius (1.32
), very strong C-F bond energy (485kJmol-1).Thereby the fluoropolymer that higher fluorine content is arranged has just presented very high hear resistance, chemical resistance, durability and weatherability, particularly for the inertness of many solvents, hydrocarbon, various soda acids, be the membrane material of the excellent performance of generally acknowledging.
About the fluoropolymer microporous barrier, forefathers have many researchs, and it is the most frequently used method of polymer microporous film of making at present that non-solvent causes phase separation method (NIPS), and it utilizes solvent and coagulating bath exchange in the preparation liquid that phase separation takes place, and obtains microcellular structure.In the majority by the pore structure that the NIPS method obtains with finger-like pore, in conjunction with local spongelike structure, the pore-size distribution broad, thus influence the separating property and the intensity of film; In addition, the solvent that the NIPS method adopts mainly is N, N NMF or N, and the N-dimethylacetylamide, this kind solvent toxicity is bigger, need carry out special protection to operating personnel, and the post processing difficulty, easily causes environmental pollution.Utilize thermally induced phase separation (TIPS) also can prepare the fluoropolymer microporous barrier, it is a kind ofly to utilize temperature change and cause the principle of Polymer Solution generation liquid-liquid phase-splitting to prepare the method for microporous barrier.The normally used diluent of TIPS method is a phthalate, as Methyl Benzene-o-dicarboxylate, butyl phthalate, and cyclohexanone, butyrolactone etc., this kind solvent generally has certain toxicity, the polymer film pore structure that obtains is still even inadequately, the loose heaped-up that presents spherocrystal has a lot of macroscopic-void defectives; When utilizing this method system film simultaneously, because easily form dense layer surface on the film surface from the high temperature cooling, surface pore structure is difficult to control, influences the separating property of film.Therefore utilize phase separation method to prepare polymer microporous film, the interaction between solvent or diluent and the polymer is the key factor that influences membrane structure.Select suitable solvent or diluent significant to the film that preparation has suitable pore structure and excellent properties; Need consider the problems such as toxicity protection, pollution and recycling of solvent or diluent in addition.
Ionic liquid is a class in room temperature or closes on the liquid organic salt of being made up of the yin, yang ion fully under the room temperature, owing to its unique physico-chemical property and functions peculiar, receives researchers' very big concern in recent years.Ionic liquid has excellent chemical stability and heat endurance, is difficult to oxidizedly, not flammable, and decomposition temperature can reach more than the 400oC; Different kinds of ions liquid is intensive polar solvent, many organic matters, inorganic matter and macromolecular material had the fine solubility energy, and vapour pressure is extremely low, volatilization hardly, and can reclaim easily and reuse, thereby be considered to " green " solvent of another very attractive after supercritical CO 2; Ionic liquid has " designability ", can design different anion/cation combinations as required, regulates ion liquid physico-chemical property and functional characteristic, and trillion kinds of possible ionic liquids of surpassing are arranged in theory.Ion liquid these unique character make it show good prospects for application at aspects such as chemical synthesis, catalysis, electrochemistry, material preparation, separation processes.
At present, the research of ionic liquid aspect membrane technology has some reports, its use mainly concentrate on the ionic liquid be the film liquid phase supported liquid membrane, to separate with polymer film, with the ionic liquid with the synthetic gas of polymerisable ionic liquid monomer be that solvent prepares natural polymer film such as cellulose, cellulose derivative and ionic liquid is the aspects such as macromolecule conductive film of conducting medium, and about ionic liquid the technical research of the structure regulating of polymer porous film be yet there are no report.Respectively ionic liquid is filled among hungarian patent HU200800093 and the Chinese patent CN101229486 in the high-molecular porous membrane material, constitutes ionic liquid " filled-type " supported liquid membrane, be used for separation of gaseous mixture.Patent DE102007002511 is fixed to the two fluoroform sulfimide salt of ionic liquid 1-butyl-3-methylimidazole in the polytetrafluoroethylporous porous membrane, is used for the sulfur-containing compound of separating liquid.Patent WO2006026064 adopts a kind of polymerisable ionic liquid monomer copolymerization to obtain a kind of gas separation membrane with high CO2 absorbability.Patent WO2009025900 report, the ionic liquid solution that is dissolved with cellulose or cellulose derivative is coated to high-molecular porous membrane material surface, afterwards ionic liquid is removed, promptly obtain coating, this composite membrane can be used for the membrane module in the liquid separation system, as ultrafiltration, nanofiltration, counter-infiltration etc.It is solvent with the ionic liquid that patent CN101234297 discloses a kind of, utilize various cellulosic materials, adopt dry-wet spinning technology spinning to prepare the cellulose hollow fiber film of mechanical strength height, stable chemical performance, in this kind method, ionic liquid only plays the effect of dissolving cellulos, also needs adding big molecule of hydrophily and organic matter pore-foaming agent just can obtain hollow-fibre membrane in addition.It is the preparation method of the cellulose membrane of solvent with the ionic liquid that patent CN101284913 has described a kind of, be about to cotton-shaped or pulverize after cellulose and the ionic liquid mixed dissolution after make film.Patent CN101380549 has put down in writing a kind of method that adopts ionic liquid to prepare blend fiber hollow fiber membranes, it mixes pulp, polyacrylonitrile copolymer, pore-foaming agent, ionic liquid, after forming stable homogeneous solution, the spinning technique processing through setting promptly obtains blend hollow fiber membrane.Disclosing a kind of among the patent CN101463137 is the method that solvent prepares natural polymer blended membrane with the ionic liquid, its ionic liquid of selecting for use can be as the cosolvent of cellulose, starch, lignin and protein, thereby make the film that is processed to form by blend not only can keep original material advantage separately, can also be by mutually combining between different molecular, play the mutual supplement with each other's advantages effect, the natural polymer blended membrane that obtained performance is better.Ionic liquid also is used to the macromolecule conductive film technical field of material.Patent CN101613481 is matrix material with the Kynoar, it and the ionic liquid monomeric compound that contains carbon-carbon double bond are dissolved in intensive polar solvent, make uniform solution, by the salivation method film forming, this film is after heat treatment, trigger monomer polymerization reaction take place and matrix macromolecule form the ion-conductive membranes of inierpeneirating network structure.Patent CN101503530 provides a kind of shitosan/ionic liquid conductive composite film, is shitosan and ionic liquid are dissolved in the distilled water with certain proportion, evaporates part moisture content again, makes solution reach gel state, gets final product behind the shaping and drying.
The characteristics of the method that this patent provided are that ionic liquid is applied in the preparation of fluoropolymer microporous barrier, select for use suitable ionic liquid to obtain preparation liquid with polymer dissolution, after mixing, after cooled with liquid nitrogen is solid, the hot pressing film forming, put in the extractant, ionic liquid is separated out again, after cleaning, the dry processing, obtain the mechanical strength height, pore-size distribution is narrow, the hole connectivity is good, porosity is high, the fluoropolymer microporous barrier of no dense layer surface.By changing ion liquid yin, yang ionic structure, can regulate and control membrane pore structure, thereby obtain various pore structure.Ionic liquid is also recyclable to be utilized again, meets the requirement of " green production ".
Summary of the invention
The purpose of this invention is to provide a kind of is the method that the system film medium prepares the fluoropolymer microporous barrier with the ionic liquid.Be that the method that the system film medium prepares the fluoropolymer microporous barrier comprises the steps: with the ionic liquid
1) be that 10.0～40.0% fluoropolymer and mass percent are that 60.0～90.0% ionic liquid adds in the high-temperature resistant container with mass percent, be heated to 100～250oC under argon shield, dissolving evenly obtains film making solution under mechanical agitation;
2) place liquid nitrogen to be cooled to solid film making solution, place then on the flat plate mold,, be pressed into film under 0.5～2.5MPa pressure, obtain ionic liquid/fluoropolymer laminated film at 100～250oC;
3) ionic liquid that compacting is formed/fluoropolymer laminated film places the extractant of 0～60oC, and ion liquid abstraction is removed, and obtains the fluoropolymer microporous barrier behind the film drying.
In such scheme of the present invention: described fluoropolymer is Kynoar, polytrifluorochloroethylene, poly-(ethylene-chlorinated) or poly-(biasfluoroethylene-hexafluoropropylene); Described ionic liquid is made up of cation and anion, cation is 1-ethyl-3-methylimidazole ion or 1-butyl-3-methylimidazole ion, and anion is tetrafluoroborate ion, hexafluorophosphoricacid acid ions, TFMS radical ion or two fluoroform sulfimide ion; Described extractant is one or both in water, the ethanol.
The invention has the beneficial effects as follows:
The present invention selects suitable ionic liquid for the system film medium, by composition, the temperature of regulating and control ion liquid kind, consumption and extractant, through phase separation, prepares high performance fluoropolymer microporous barrier.The ionic liquid that the present invention selects for use is " green solvent ", volatilization hardly, have excellent chemical stability and heat endurance, and the water-soluble or ethanol isopolarity solvent of energy, need not to use any organic solvent to make extractant, and also recyclable recycling meets requirements of green environmental protection, greatly reduces production cost again.The fluoropolymer microporous barrier aperture of the present invention preparation is adjustable, even aperture distribution, the hole connectivity is good, porosity is high, and the no densified cortex in surface can be widely used in aspects such as chemical industry, environmental protection, bio-pharmaceuticals, health care and industry water purified treatment.
Description of drawings
The electron scanning micrograph (upper surface) of the polyvinylidene fluoride microporous film that Fig. 1 prepares for the embodiment of the invention 2;
The electron scanning micrograph (lower surface) of the polyvinylidene fluoride microporous film that Fig. 2 prepares for the embodiment of the invention 2;
The electron scanning micrograph (section) of the polyvinylidene fluoride microporous film that Fig. 3 prepares for the embodiment of the invention 2;
The electron scanning micrograph (upper surface) of poly-(biasfluoroethylene-hexafluoropropylene) microporous barrier that Fig. 4 prepares for the embodiment of the invention 6;
The electron scanning micrograph (lower surface) of poly-(biasfluoroethylene-hexafluoropropylene) microporous barrier that Fig. 5 prepares for the embodiment of the invention 6;
The electron scanning micrograph (section) of poly-(biasfluoroethylene-hexafluoropropylene) microporous barrier that Fig. 6 prepares for the embodiment of the invention 6;
The specific embodiment
Provided by the invention a kind of be that the system film medium prepares the method for fluoropolymer microporous barrier with the ionic liquid, form by three steps, the specific embodiment of each step is followed successively by:
1) be that 10.0～40.0% fluoropolymer and mass percent are that 60.0～90.0% ionic liquid adds in the high-temperature resistant container with mass percent, be heated to 100～250oC under argon shield, dissolving evenly obtains film making solution under mechanical agitation.
Optimum condition is: the quality percentage composition of fluoropolymer is 15%～35% in the mixture, and heating-up temperature is 120～230oC.
2) place liquid nitrogen to be cooled to solid film making solution, place then on the flat plate mold, under 100～250oC, be pressed into film under 0.5～2.5MPa pressure, obtain ionic liquid/fluoropolymer laminated film.
Optimum condition is: hot pressing temperature is 120～230oC, and pressure is 1.0～2.0MPa
3) ionic liquid that compacting is formed/fluoropolymer laminated film places the extractant of 0～60oC, and ion liquid abstraction is removed, and obtains the fluoropolymer microporous barrier behind the film drying.
Optimum condition is: the temperature of extractant is 0～30oC.
After film preparation finishes, can separate containing ion liquid extractant rectifying, so that ionic liquid is recycled.
The invention will be further described below in conjunction with embodiment and accompanying drawing, but described embodiment is not construed as limiting the invention for example.Among the present invention, ionic liquid is the material of most critical, because ionic liquid has the fine solubility energy to many organic matters, inorganic matter and macromolecular material, therefore can also in system, add a certain amount of cosolvent, hydrophilic modification reagent, antioxidant and film for additive or the like according to the production application needs.
Embodiment 1:
With the quality percentage composition is that 10% Kynoar (weight average molecular weight 360,000) and quality percentage composition are that ionic liquid 1-ethyl-3-methyl imidazolium tetrafluoroborate ([EMIM] BF4) of 90% adds in the high-temperature resistant container, under argon shield, be warming up to 100oC, dissolving evenly obtains film making solution under mechanical agitation; Place liquid nitrogen to be cooled to solid film making solution, place then on the flat plate mold,, be pressed into film under the 0.5MPa pressure, obtain ionic liquid/Kynoar laminated film at 100oC; The water of again laminated film being put into 0oC extracts, and handles 72 hours, changes the single extraction agent in per 12 hours, and ionic liquid is extracted to be removed, and film obtains polyvinylidene fluoride microporous film after drying.
Make the thickness 40 μ m of film, average pore size is 1.5 μ m, and porosity is 72%, and the film surface does not have dense layer surface.
Embodiment 2:
With the quality percentage composition is that 20% Kynoar (weight average molecular weight 360,000) and quality percentage composition are that ionic liquid 1-butyl-3-methylimidazole hexafluorophosphate ([BMIM] PF6) of 80% joins in the high-temperature resistant container, under argon shield, be warming up to 120oC, dissolving evenly obtains film making solution under mechanical agitation; Place liquid nitrogen to be cooled to solid film making solution, place then on the flat plate mold,, be pressed into film under the 1.5MPa pressure, obtain ionic liquid/Kynoar laminated film at 120oC; The ethanol of again laminated film being put into 0oC extracts, and handles 72 hours, changes the single extraction agent in per 12 hours, and ionic liquid is extracted to be removed, and obtains polyvinylidene fluoride microporous film behind the film drying.
Make the thickness 60 μ m of film, average pore size is 0.9 μ m, and porosity is 65%, and the film surface does not have dense layer surface.
Embodiment 3:
With the quality percentage composition is that 40% Kynoar (weight average molecular weight 360,000) and quality percentage composition are that 60% two fluoroform sulfimide salt ([BMIM] TF2N) of ionic liquid 1-butyl-3-methylimidazole join in the high-temperature resistant container, under argon shield, be warming up to 200oC, dissolving evenly obtains film making solution under mechanical agitation; Place liquid nitrogen to be cooled to solid film making solution, place then on the flat plate mold,, be pressed into film under the 2.0MPa pressure, obtain ionic liquid/Kynoar laminated film at 200oC; Laminated film is put into the water of 20oC and the mixed extractant of ethanol (volume fraction of water is 25%) again, handled 48 hours, changed the single extraction agent in per 12 hours, ionic liquid is extracted to be removed, and obtains polyvinylidene fluoride microporous film behind the film drying.
Make the thickness 65 μ m of film, average pore size is 2.0 μ m, and porosity is 60%, and the film surface does not have dense layer surface.
Embodiment 4:
With the quality percentage composition is that 10% polytrifluorochloroethylene (weight average molecular weight 300,000) and quality percentage composition are that ionic liquid 1-butyl-3-methylimidazole hexafluorophosphate ([BMIM] PF6) of 90% joins in the high-temperature resistant container, under argon shield, be warming up to 200oC, dissolving evenly obtains film making solution under mechanical agitation; Place liquid nitrogen to be cooled to solid film making solution, place on the flat plate mold then, at 200oC, 1.0MPa be pressed into film under the pressure, obtain ionic liquid/polytrifluorochloroethylene laminated film, the water of putting into 60oC immediately extracts, handled 72 hours, changed the single extraction agent in per 12 hours, ionic liquid is extracted to be removed, and obtains the polytrifluorochloroethylene microporous barrier behind the film drying.
Make the thickness 100 μ m of film, average pore size is 0.3 μ m, and porosity is 68%, and the film surface does not have dense layer surface.
Embodiment 5:
With the quality percentage composition is that 20% polytrifluorochloroethylene (weight average molecular weight 300,000) and quality percentage composition are that 80% two fluoroform sulfimide salt ([BMIM] TF2N) of ionic liquid 1-butyl-3-methylimidazole join in the high-temperature resistant container, under argon shield, be warming up to 230oC, dissolving evenly obtains film making solution under mechanical agitation; Place liquid nitrogen to be cooled to solid film making solution, place on the flat plate mold then, at 230oC, 1.0MPa be pressed into film under the pressure, obtain ionic liquid/polytrifluorochloroethylene laminated film, the ethanol of putting into 30oC immediately extracts, handled 72 hours, changed the single extraction agent in per 12 hours, ionic liquid is extracted to be removed, and obtains the polytrifluorochloroethylene microporous barrier behind the film drying.
Make the thickness 110 μ m of film, average pore size is 0.5 μ m, and porosity is 70%, and the film surface does not have dense layer surface.
Embodiment 6:
With the quality percentage composition is that 15% poly-(biasfluoroethylene-hexafluoropropylene) (weight average molecular weight is 130,000) and quality percentage composition are that ionic liquid 1-ethyl-3-methylimidazole fluoroform sulphonate ([EMIM] OTF) of 85% joins in the high-temperature resistant container, under argon shield, be warming up to 160oC, dissolving evenly obtains film making solution under mechanical agitation; Place liquid nitrogen to be cooled to solid film making solution, place then on the flat plate mold,, be pressed into film under the 1.5MPa pressure, obtain ionic liquid/poly-(biasfluoroethylene-hexafluoropropylene) laminated film at 160oC; The water of again laminated film being put into 30oC extracts, and handles 72 hours, changes the single extraction agent, and after ionic liquid is extracted and removes, is gathered (biasfluoroethylene-hexafluoropropylene) microporous barrier behind the film drying in per 12 hours.
Make the thickness 50 μ m of film, average pore size is 1.5 μ m, and porosity is 62%, and the film surface does not have dense layer surface.
Embodiment 7:
With the quality percentage composition is that 40% poly-(biasfluoroethylene-hexafluoropropylene) (weight average molecular weight is 130,000) and quality percentage composition are that ionic liquid 1-butyl-3-methyl imidazolium tetrafluoroborate ([BMIM] BF4) of 60% joins in the high-temperature resistant container, under argon shield, be warming up to 250oC, dissolving evenly obtains film making solution under mechanical agitation; Place liquid nitrogen to be cooled to solid film making solution, place then on the flat plate mold,, be pressed into film under the 2.5MPa pressure, obtain ionic liquid/poly-(biasfluoroethylene-hexafluoropropylene) laminated film at 250oC; Again laminated film is put into the water of 60oC, handled 48 hours, changed the single extraction agent, and after ionic liquid is extracted and removes, gathered (biasfluoroethylene-hexafluoropropylene) microporous barrier behind the film drying in per 12 hours.
Make the thickness 75 μ m of film, average pore size is 0.8 μ m, and porosity is 56%, and the film surface does not have dense layer surface.
Embodiment 8:
With the quality percentage composition is that 10% poly-(ethylene-chlorinated) (weight average molecular weight 80,000) and quality percentage composition are that ionic liquid 1-ethyl-3-methylimidazole fluoroform sulphonate ([EMIM] OTF) of 90% joins in the high-temperature resistant container, under argon shield, be warming up to 180oC, dissolving evenly obtains film making solution under mechanical agitation; Place liquid nitrogen to be cooled to solid film making solution, place then on the flat plate mold,, be pressed into film under the 1.5MPa pressure, obtain ionic liquid/poly-(ethylene-chlorinated) laminated film at 180oC; Again laminated film is put into the ethanol of 30oC, handled 48 hours, changed the single extraction agent, and after ionic liquid is extracted and removes, gathered (ethylene-chlorinated) microporous barrier behind the film drying in per 12 hours.
Make the thickness 80 μ m of film, average pore size is 2.5 μ m, and porosity is 68%, and the film surface does not have dense layer surface.
Embodiment 9:
With the quality percentage composition is that 15% poly-(ethylene-chlorinated) (weight average molecular weight 80,000) and quality percentage composition are that ionic liquid 1-butyl-3-methylimidazole fluoroform sulphonate ([BMIM] OTF) of 85% joins in the high-temperature resistant container, under argon shield, be warming up to 200oC, dissolving evenly obtains film making solution under mechanical agitation; Place liquid nitrogen to be cooled to solid film making solution, place then on the flat plate mold,, be pressed into film under the 2.0MPa pressure, obtain ionic liquid/poly-(ethylene-chlorinated) laminated film at 200oC; Again laminated film is put into the ethanol of 30oC, handled 48 hours, changed the single extraction agent, and after ionic liquid is extracted and removes, gathered (ethylene-chlorinated) microporous barrier behind the film drying in per 12 hours.
Make the thickness 45 μ m of film, average pore size is 1.5 μ m, and porosity is 58%, and the film surface does not have dense layer surface.
Embodiment 10:
With the quality percentage composition is that 25% poly-(ethylene-chlorinated) (weight average molecular weight 80,000) and quality percentage composition are that ionic liquid 1-butyl-3-methylimidazole pair fluoroform sulfimide salt ([BMIM] TF2N) of 75% join in the high-temperature resistant container, under argon shield, be warming up to 250oC, dissolving evenly obtains film making solution under mechanical agitation; Place liquid nitrogen to be cooled to solid film making solution, place then on the flat plate mold,, be pressed into film under the 2.5MPa pressure, obtain ionic liquid/poly-(ethylene-chlorinated) laminated film at 250oC; Again laminated film is put into the water of 30oC and the mixed extractant of ethanol (volume fraction of water is 50%), handled 48 hours, changed the single extraction agent in per 12 hours, after ionic liquid was extracted and removes, film drying was gathered (ethylene-chlorinated) microporous barrier.
Make the thickness 55 μ m of film, average pore size is that 1.2 μ m porositys are 62%, and the film surface does not have dense layer surface.
Claims (2)
1. one kind is the method that the system film medium prepares the fluoropolymer microporous barrier with the ionic liquid, it is characterized in that comprising the steps:
1) be that 10.0～40.0% fluoropolymer and mass percent are that 60.0～90.0% ionic liquid adds in the high-temperature resistant container with mass percent, be heated to 100～250 ℃ under argon shield, dissolving evenly obtains film making solution under mechanical agitation;
2) place liquid nitrogen to be cooled to solid film making solution, place then on the flat plate mold,, be pressed into film under 0.5～2.5MPa pressure, obtain ionic liquid/fluoropolymer laminated film at 100～250 ℃;
3) ionic liquid that compacting is formed/fluoropolymer laminated film places 0～60 ℃ extractant, and ion liquid abstraction is removed, and obtains the fluoropolymer microporous barrier behind the film drying;
Described ionic liquid is made up of cation and anion, cation is 1-ethyl-3-methylimidazole ion or 1-butyl-3-methylimidazole ion, anion is tetrafluoroborate ion, hexafluorophosphoricacid acid ions, TFMS radical ion or two fluoroform sulfimide radical ion, and described extractant is one or both in water or the ethanol.
2. according to claim 1 a kind of be that the system film medium prepares the method for fluoropolymer microporous barrier with the ionic liquid, it is characterized in that described fluoropolymer is Kynoar, polytrifluorochloroethylene, poly-(ethylene-chlorinated) or poly-(biasfluoroethylene-hexafluoropropylene).
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