CN114870653A - Porous polytetrafluoroethylene membrane with asymmetric wettability and preparation method thereof - Google Patents

Porous polytetrafluoroethylene membrane with asymmetric wettability and preparation method thereof Download PDF

Info

Publication number
CN114870653A
CN114870653A CN202210577388.6A CN202210577388A CN114870653A CN 114870653 A CN114870653 A CN 114870653A CN 202210577388 A CN202210577388 A CN 202210577388A CN 114870653 A CN114870653 A CN 114870653A
Authority
CN
China
Prior art keywords
membrane
polytetrafluoroethylene
porous
acid polymer
substrate
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202210577388.6A
Other languages
Chinese (zh)
Other versions
CN114870653B (en
Inventor
徐志梁
李勇进
洪蒋涛
胡群义
罗文春
余红方
俞文远
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Zhejiang Saixun Environmental Protection Technology Co ltd
Original Assignee
Zhejiang Saixun Environmental Protection Technology Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Zhejiang Saixun Environmental Protection Technology Co ltd filed Critical Zhejiang Saixun Environmental Protection Technology Co ltd
Priority to CN202210577388.6A priority Critical patent/CN114870653B/en
Publication of CN114870653A publication Critical patent/CN114870653A/en
Application granted granted Critical
Publication of CN114870653B publication Critical patent/CN114870653B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D71/00Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/06Organic material
    • B01D71/66Polymers having sulfur in the main chain, with or without nitrogen, oxygen or carbon only
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D67/00Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
    • B01D67/0081After-treatment of organic or inorganic membranes
    • B01D67/0088Physical treatment with compounds, e.g. swelling, coating or impregnation
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D69/00Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
    • B01D69/02Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor characterised by their properties
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D71/00Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/06Organic material
    • B01D71/30Polyalkenyl halides
    • B01D71/32Polyalkenyl halides containing fluorine atoms
    • B01D71/36Polytetrafluoroethene
    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30Hydrogen technology
    • Y02E60/50Fuel cells

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Inorganic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
  • Separation Using Semi-Permeable Membranes (AREA)

Abstract

A porous polytetrafluoroethylene membrane with asymmetric wettability and a preparation method thereof, wherein the method comprises the following steps: 1) placing a polytetrafluoroethylene film substrate with a porous structure on a heat source to heat a single surface of the film substrate; 2) taking a perfluorosulfonic acid polymer solution containing a low-boiling point solvent as a modifier to coat the non-heated surface of the film substrate, volatilizing the solvent, and preparing the polytetrafluoroethylene porous film with asymmetric wettability formed by compounding the film substrate and the fluorosulfonic acid film. The preparation method of the polytetrafluoroethylene porous membrane with asymmetric wettability is simple, efficient and controllable, and the perfluorosulfonic acid polymer solution containing the low-boiling-point solvent is coated on one side of the porous membrane, and the low-boiling-point solvent is quickly volatilized at a certain temperature in the process of heating the single side of the porous membrane, so that the content of the perfluorosulfonic acid polymer is in gradient distribution along the thickness direction of the thin membrane substrate, and the asymmetric wettability structure in the ultrathin thin membrane substrate is realized.

Description

Porous polytetrafluoroethylene membrane with asymmetric wettability and preparation method thereof
Technical Field
The invention relates to the field of preparation of high polymer materials, in particular to a polytetrafluoroethylene porous membrane with asymmetric wettability and a preparation method thereof.
Background
The polymer asymmetric wettability porous membrane has great application potential in the fields of membrane separation, membrane distillation, emulsification and the like, so the preparation method thereof is widely concerned. According to different application fields of the porous membrane with the asymmetric wettability of the polymer, the preparation of the membrane asymmetric wettability structure is the key point for the preparation of the porous membrane with the asymmetric wettability of the polymer. In the practical use process of the polymer asymmetric wettability porous separation membrane, the preparation of the asymmetric wettability structure becomes a core problem of the asymmetric wettability thin film. The structure of asymmetric wettability determines the fractional efficiency, while the film thickness determines the film resistance, and therefore there is often no compromise between film thickness and asymmetric manufacturing.
Therefore, it is necessary to develop an asymmetric wetting film having excellent properties and a method for producing the same.
Disclosure of Invention
Based on the above, the invention provides a polytetrafluoroethylene porous membrane with asymmetric wettability and a preparation method thereof, which are used for solving the technical problem that the film thickness and asymmetric manufacture of the polymer porous membrane with asymmetric wettability in the prior art cannot be compatible.
In order to achieve the purpose, the invention provides a polytetrafluoroethylene porous membrane with asymmetric wettability, which comprises a membrane substrate and perfluorosulfonic acid polymer compounded in the membrane substrate, wherein the membrane substrate is made of polytetrafluoroethylene and has a porous structure, and the content of the perfluorosulfonic acid polymer is distributed in a gradient manner along the thickness direction of the membrane substrate.
In a more preferred embodiment of the present invention, the thickness of the thin film substrate is 6 μm to 10 μm.
According to another aspect of the present invention, there is also provided a method for preparing a porous polytetrafluoroethylene membrane with asymmetric wettability, comprising the steps of:
1) placing a polytetrafluoroethylene film substrate with a porous structure on a heat source to heat a single surface of the film substrate;
2) and taking a perfluorosulfonic acid polymer solution containing a low-boiling point solvent as a modifier to coat the non-heated surface of the film substrate, and heating the low-boiling point solvent to quickly volatilize so as to prepare the polytetrafluoroethylene porous film with asymmetric wettability, which is formed by compounding the film substrate and the fluorosulfonic acid film.
In a further preferred embodiment of the present invention, the heat source is a heat stage, and the heating temperature of the heat stage is higher than the boiling point of the low boiling point solvent in the perfluorosulfonic acid polymer solution.
In a further preferred embodiment of the present invention, the heating temperature of the hot stage is 200 ℃.
As a further preferable embodiment of the present invention, in the step 2), after the film substrate is heated at the predetermined heating temperature for at least one minute, the coating of the perfluorosulfonic acid polymer solution is performed.
In a further preferred embodiment of the present invention, the low boiling point solvent in the perfluorosulfonic acid polymer solution includes ethanol.
As a further preferable technical scheme of the invention, the concentration of the perfluorinated sulfonic acid polymer solution is 6-10%.
In a further preferred embodiment of the present invention, the concentration of the perfluorosulfonic acid polymer solution is 8%.
As a further preferable technical scheme of the invention, the film matrix is paved above a heat source when being heated, the bottom surface of the film matrix is a heated surface, the top surface of the film matrix is a non-heated surface, and the perfluorosulfonic acid polymer solution is coated on the top surface of the film matrix.
The polytetrafluoroethylene porous membrane with asymmetric wettability and the preparation method thereof can achieve the following beneficial effects by adopting the technical scheme:
1) the polytetrafluoroethylene porous membrane has better chemical corrosion resistance and supporting property, and the membrane can realize opposite wettability to oil under water;
2) the polytetrafluoroethylene porous membrane has an asymmetric wettability membrane, can realize one-way transmission of oil, and has better performance on oil separation in an oil-water mixed system;
3) the polytetrafluoroethylene porous membrane can be used in the fields of environmental protection, industry and the like, and the specific wettability can be adjusted according to application;
4) the preparation method is simple, efficient and controllable, and by coating the perfluorinated sulfonic acid polymer solution containing the low-boiling-point solvent on one side and utilizing the low-boiling-point solvent to rapidly volatilize at a certain temperature in the process of heating the single side, the content of the perfluorinated sulfonic acid polymer is in gradient distribution along the thickness direction of the film substrate, so that the asymmetric wettability structure in the ultrathin film substrate is realized.
Drawings
The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.
FIG. 1 shows the morphology of a polytetrafluoroethylene porous membrane according to the invention before and after macroscopic coating;
FIG. 2 is a scanned front and back views of a polytetrafluoroethylene porous membrane of the invention before coating, wherein the scale is 10 μm;
FIG. 3 is a scanned front and back views of the polytetrafluoroethylene porous membrane of the invention after coating, wherein the scale is 10 μm;
FIG. 4 is the underwater oil contact angles of the front and back sides before the polytetrafluoroethylene porous membrane is coated, wherein the oil is heavy oil carbon tetrachloride;
FIG. 5 shows the contact angles of the oil on the front and back sides of the polytetrafluoroethylene porous membrane coated with the oil of the invention, wherein the oil is heavy oil carbon tetrachloride.
The objects, features and advantages of the present invention will be further explained with reference to the accompanying drawings.
Detailed Description
The invention will be further described with reference to the accompanying drawings and specific embodiments. In the preferred embodiments, the terms "upper", "lower", "left", "right", "middle" and "a" are used for clarity of description only, and are not used to limit the scope of the invention, and the relative relationship between the terms and the terms is not changed or modified substantially without changing the technical content of the invention.
The invention provides a polytetrafluoroethylene porous membrane with asymmetric wettability (referred to as polytetrafluoroethylene porous membrane for short), which comprises a membrane substrate and perfluorosulfonic acid polymer compounded in the membrane substrate, wherein the content of the perfluorosulfonic acid polymer is in gradient distribution along the thickness direction of the membrane substrate, the membrane substrate is made of polytetrafluoroethylene and has a porous structure, the thickness of the membrane substrate is 6-10 mu m, and the membrane substrate determines the thickness of the polytetrafluoroethylene porous membrane.
The porous polytetrafluoroethylene membrane of the invention has the above structure, so that the porous polytetrafluoroethylene membrane has the following excellent characteristics: the hydrophilicity is provided by the wettability of the perfluorosulfonic acid polymer, the hydrophobicity is provided by the wettability of the polytetrafluoroethylene material, and the asymmetric wettability is provided by the gradient distribution of the content of the perfluorosulfonic acid polymer.
The invention also provides a preparation method of the polytetrafluoroethylene porous membrane with asymmetric wettability, which comprises the following steps:
1) flatly paving a polytetrafluoroethylene film substrate with a porous structure above a heat source, and heating a single surface of the film substrate by taking the bottom surface of the film substrate as a heated surface;
2) taking the top surface of the film substrate as a non-heated surface, taking a perfluorosulfonic acid polymer solution containing a low-boiling point solvent as ethanol as a modifier to coat the non-heated surface of the film substrate, and heating the low-boiling point solvent to quickly volatilize so as to prepare the polytetrafluoroethylene porous membrane with asymmetric wettability, which is formed by compounding the film substrate and the fluorosulfonic acid membrane.
In one embodiment, the heat source is a heat block and the heating temperature of the heat block is greater than the boiling point of the low boiling solvent in the perfluorosulfonic acid polymer solution.
In the actual heating process, if the temperature is too low, the low-boiling-point solvent is not volatilized quickly, so that the perfluorosulfonic acid polymer solution can quickly permeate to the other side of the film substrate after being coated, and the prepared film is a symmetrical wetting film instead of an asymmetrical wetting film; if the temperature is too high, damage to the membrane itself may result, while the modifier perfluorosulfonic acid polymer solution tends to concentrate on the surface and block the pores. The temperature is therefore chosen so that the properties of asymmetric wettability are not present, nor is the membrane itself damaged or the clogging of the pores leading to a decrease in flux. In specific implementation, the heating temperature range is 150-250 ℃. Preferably, the heating temperature of the heat stage is 200 ℃. In the adding process, the film substrate is heated at a preset heating temperature for at least one minute, and then the perfluorosulfonic acid polymer solution is coated.
In actual use, if the concentration of the perfluorosulfonic acid polymer solution is too high, the phenomenon of membrane pore blocking can be caused, if the concentration is too low, the same effect can be achieved, and more times of coating are needed, so that the cost is increased and the energy is wasted. In specific implementation, the concentration of the perfluorinated sulfonic acid polymer solution is 6-10%. Preferably, the concentration of the perfluorosulfonic acid polymer solution is 8%.
In the preparation process, a heat source is added below the film substrate, the film substrate is coated, the solvent of the perfluorinated sulfonic acid polymer solution is ethanol, the ethanol can be rapidly volatilized under the heating of the heat source below, the temperature of the heat source is high, the solvent is rapidly volatilized when the perfluorinated sulfonic acid polymer solution does not permeate the bottom surface of the film substrate, and therefore the perfluorinated sulfonic acid polymer is in gradient distribution along the thickness direction of the film substrate, and the wettability of the front surface and the back surface of the prepared polytetrafluoroethylene porous membrane is asymmetric. The low-boiling-point solvent is utilized to volatilize rapidly at a certain temperature, and after the single-side coating is carried out, the content of the perfluorosulfonic acid polymer presents gradient distribution along the thickness direction of the film substrate, which is the main innovative technical characteristic of the invention.
In order to allow those skilled in the art to better understand the advantageous effects of the present invention, the following tests were performed on the porous polytetrafluoroethylene membrane prepared in one example according to the preparation method of the present invention:
referring to fig. 1, in the macro-chart, the surface of the modified film substrate does not have the phenomenon of hole blocking, and if the surface of the film substrate is not pure white, the film substrate macro is transparent.
Referring to fig. 2-5, in the microscopic view, the pore diameter and the pores of the modified film substrate surface are not significantly changed, and the pore blocking phenomenon is not occurred, and the material is not damaged; the film substrate before and after coating shows the wettability of a pure polytetrafluoroethylene film, both surfaces show an underwater oleophilic state, after coating modification, the film substrate shows an underwater oleophobic property of a coated surface (a front surface shown in the figure) and an underwater oleophilic state of an uncoated surface (a back surface shown in the figure), so that the characteristic of asymmetric wettability of the two surfaces of the film is achieved, and a contact angle diagram of the phenomenon is shown in figure 5, wherein the wettability of the polytetrafluoroethylene porous film to oil underwater is 36 degrees and the oleophilic surface is 133.7 degrees.
In practical application, the wettability of the polytetrafluoroethylene porous membrane can be adjusted according to requirements, which are respectively as follows: the coating surface can be subjected to wettability regulation and control by using different concentrations of the modifier, the coating surface can be subjected to wettability regulation and control by using different temperatures, the coating surface can be subjected to wettability regulation and control by using different coating times, and the uncoated surface can be subjected to wettability regulation and control by using different base films instead of a polytetrafluoroethylene film.
Polytetrafluoroethylene has excellent chemical resistance, high temperature resistance and excellent flexibility, and is often used as a material of choice for polymer separation membranes. The porous separation membrane with asymmetric wettability is prepared by adopting a polytetrafluoroethylene film substrate with a porous structure and a thickness less than ten microns, heating the single surface of a heating table and coating the non-heated surface, and can be applied to multiple fields of oil-water separation, membrane distillation, emulsification and the like.
Although specific embodiments of the present invention have been described above, it will be appreciated by those skilled in the art that these are merely examples and that many variations or modifications may be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims.

Claims (10)

1. The polytetrafluoroethylene porous membrane with asymmetric wettability is characterized by comprising a membrane substrate and a perfluorosulfonic acid polymer compounded in the membrane substrate, wherein the membrane substrate is made of polytetrafluoroethylene and has a porous structure, and the content of the perfluorosulfonic acid polymer is distributed in a gradient manner along the thickness direction of the membrane substrate.
2. The porous polytetrafluoroethylene membrane with asymmetric wettability according to claim 1, wherein the thickness of said film base is 6 μm to 10 μm.
3. A method for producing a porous polytetrafluoroethylene membrane with asymmetric wettability according to claim 1 or 2, comprising the steps of:
1) placing a polytetrafluoroethylene film substrate with a porous structure on a heat source to heat a single surface of the film substrate;
2) and taking a perfluorosulfonic acid polymer solution containing a low-boiling point solvent as a modifier to coat the non-heated surface of the film substrate, and heating the low-boiling point solvent to quickly volatilize so as to prepare the polytetrafluoroethylene porous film with asymmetric wettability, which is formed by compounding the film substrate and the fluorosulfonic acid film.
4. The method of claim 3, wherein the heat source is a heat stage, and the heating temperature of the heat stage is higher than the boiling point of the low boiling point solvent in the perfluorosulfonic acid polymer solution.
5. The method of preparing a porous membrane of polytetrafluoroethylene with asymmetric wettability as claimed in claim 4, wherein a heating temperature of said hot stage is 200 ℃.
6. The method of preparing a porous membrane of polytetrafluoroethylene with asymmetric wettability as set forth in claim 3, wherein the coating of the perfluorosulfonic acid polymer solution is carried out after the membrane substrate is heated at a predetermined heating temperature for at least one minute in step 2).
7. The method of preparing a porous membrane of polytetrafluoroethylene with asymmetric wettability according to claim 3, wherein said low boiling point solvent in said perfluorosulfonic acid polymer solution comprises ethanol.
8. The method for producing a porous polytetrafluoroethylene membrane with asymmetric wettability according to claim 3, wherein the concentration of said perfluorosulfonic acid polymer solution is 6 to 10%.
9. The method for producing a porous polytetrafluoroethylene membrane with asymmetric wettability according to claim 8, wherein said perfluorosulfonic acid polymer solution is at a concentration of 8%.
10. The method for preparing a porous polytetrafluoroethylene membrane with asymmetric wettability as claimed in any one of claims 3 to 9, wherein said membrane substrate is laid on top of a heat source while being heated, the bottom surface of the membrane substrate is a heated surface, the top surface of the membrane substrate is a non-heated surface, and a perfluorosulfonic acid polymer solution is applied to the top surface of the membrane substrate.
CN202210577388.6A 2022-05-25 2022-05-25 Polytetrafluoroethylene porous membrane with asymmetric wettability and preparation method thereof Active CN114870653B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210577388.6A CN114870653B (en) 2022-05-25 2022-05-25 Polytetrafluoroethylene porous membrane with asymmetric wettability and preparation method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210577388.6A CN114870653B (en) 2022-05-25 2022-05-25 Polytetrafluoroethylene porous membrane with asymmetric wettability and preparation method thereof

Publications (2)

Publication Number Publication Date
CN114870653A true CN114870653A (en) 2022-08-09
CN114870653B CN114870653B (en) 2023-07-11

Family

ID=82677814

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210577388.6A Active CN114870653B (en) 2022-05-25 2022-05-25 Polytetrafluoroethylene porous membrane with asymmetric wettability and preparation method thereof

Country Status (1)

Country Link
CN (1) CN114870653B (en)

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5653882A (en) * 1993-07-16 1997-08-05 E. I. Du Pont De Nemours And Company Asymmetric membranes of polytetrafluoroethylene and process for making them
CN101733016A (en) * 2009-12-10 2010-06-16 山东东岳神舟新材料有限公司 Functional group grafted porous membrane compound perfluorinated ion exchange membrane
CN101797482A (en) * 2008-12-05 2010-08-11 通用电气公司 The preparation method of asymmetric composite membrane
CN101961608A (en) * 2010-10-12 2011-02-02 浙江理工大学 Method for controlling aperture of polytetrafluoroethylene hollow fibrous membrane
CN102068924A (en) * 2010-12-22 2011-05-25 中国科学院长春应用化学研究所 Polytetrafluoroethylene composite membrane and preparation method thereof
US20110186437A1 (en) * 2010-02-02 2011-08-04 James Huang Polymeric Electret Film and Method of Manufacturing the Same
CN107096390A (en) * 2017-05-17 2017-08-29 四川理工学院 A kind of preparation method of modified copolymer perforated membrane
CN108511777A (en) * 2018-04-04 2018-09-07 华南理工大学 The construction method of proton exchange membrane with three-dimensional high-specific surface area surface and its high-performance membrane electrode based on this proton exchange membrane

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5653882A (en) * 1993-07-16 1997-08-05 E. I. Du Pont De Nemours And Company Asymmetric membranes of polytetrafluoroethylene and process for making them
CN101797482A (en) * 2008-12-05 2010-08-11 通用电气公司 The preparation method of asymmetric composite membrane
CN101733016A (en) * 2009-12-10 2010-06-16 山东东岳神舟新材料有限公司 Functional group grafted porous membrane compound perfluorinated ion exchange membrane
US20110186437A1 (en) * 2010-02-02 2011-08-04 James Huang Polymeric Electret Film and Method of Manufacturing the Same
CN101961608A (en) * 2010-10-12 2011-02-02 浙江理工大学 Method for controlling aperture of polytetrafluoroethylene hollow fibrous membrane
CN102068924A (en) * 2010-12-22 2011-05-25 中国科学院长春应用化学研究所 Polytetrafluoroethylene composite membrane and preparation method thereof
CN107096390A (en) * 2017-05-17 2017-08-29 四川理工学院 A kind of preparation method of modified copolymer perforated membrane
CN108511777A (en) * 2018-04-04 2018-09-07 华南理工大学 The construction method of proton exchange membrane with three-dimensional high-specific surface area surface and its high-performance membrane electrode based on this proton exchange membrane

Also Published As

Publication number Publication date
CN114870653B (en) 2023-07-11

Similar Documents

Publication Publication Date Title
CN107126851B (en) A kind of complex reverse osmosis membrane and preparation method thereof
Liu et al. High-performance polyamide/ceramic hollow fiber TFC membranes with TiO2 interlayer for pervaporation dehydration of isopropanol solution
England et al. Surface roughness rather than surface chemistry essentially affects insect adhesion
US5266391A (en) Composite porous membranes
US20230256397A1 (en) Dual-layer membrane
Lu et al. Low‐Density Polyethylene (LDPE) Surface With a Wettability Gradient by Tuning its Microstructures
US9139739B2 (en) Method for preparing micro-patterned superhydrophobic/superhydrophilic coatings
Kim et al. Large-Area Ti3C2T x-MXene coating: toward industrial-scale fabrication and molecular separation
Cheng et al. Janus copper mesh film with unidirectional water transportation ability toward high efficiency oil/water separation
KR950031192A (en) Microporous membranes made of amorphous polymers and methods for their preparation
Wang et al. Development and impact of sandwich wettability structure for gas distribution media on PEM fuel cell performance
CN106582314B (en) A kind of small-bore hydrophobic composite membrane preparation method for membrane distillation
TWI317363B (en) Composite membranes containing polytetrafluoroethylene and method for forming the same
CN107469650B (en) Preparation method of hydrophobic macroporous polyimide nanofiber forward osmosis membrane
KR102465270B1 (en) Method of producing porous body of ethylene-vinyl alcohol copolymer
Song et al. Ethanol‐responsive characteristics of polyethersulfone composite membranes blended with poly (N‐isopropylacrylamide) nanogels
Mizukoshi et al. Control over wettability of textured surfaces by electrospray deposition
CN114870653B (en) Polytetrafluoroethylene porous membrane with asymmetric wettability and preparation method thereof
CN1272114C (en) Method for preparing super hydrophobic polymeric coating using non-crystalline polymer
CN107413208B (en) A kind of preparation method of highly selective gasoline desulfurizing film
CN116371221B (en) Polyamide nanofiltration membrane and preparation method and application thereof
JP7180830B2 (en) Porous fluororesin composite membrane and method for producing the same
Siegel et al. Roll‐to‐Roll Fabrication of Bijels via Solvent Transfer Induced Phase Separation (R2R‐STrIPS)
JP2009211942A (en) Proton transport material, its manufacturing material, ion exchanger using it, membrane-electrode assembly, and fuel cell
CN114768549B (en) High-pressure deformation resistant porous membrane capable of being used as distillation membrane and preparation method thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant