CN112808032A - Method for enhancing hydrophobic property of PVDF hollow fiber membrane - Google Patents
Method for enhancing hydrophobic property of PVDF hollow fiber membrane Download PDFInfo
- Publication number
- CN112808032A CN112808032A CN202011620243.7A CN202011620243A CN112808032A CN 112808032 A CN112808032 A CN 112808032A CN 202011620243 A CN202011620243 A CN 202011620243A CN 112808032 A CN112808032 A CN 112808032A
- Authority
- CN
- China
- Prior art keywords
- hollow fiber
- fiber membrane
- pvdf
- pvdf hollow
- hydrophobic property
- 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.)
- Pending
Links
Images
Classifications
-
- 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
- B01D71/30—Polyalkenyl halides
- B01D71/32—Polyalkenyl halides containing fluorine atoms
- B01D71/34—Polyvinylidene fluoride
-
- 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
- B01D67/0079—Manufacture of membranes comprising organic and inorganic components
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
- B01D69/02—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor characterised by their properties
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
- B01D69/08—Hollow fibre membranes
-
- 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
- B01D71/02—Inorganic material
- B01D71/021—Carbon
-
- 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
- B01D71/30—Polyalkenyl halides
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2325/00—Details relating to properties of membranes
- B01D2325/38—Hydrophobic membranes
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Inorganic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
- Artificial Filaments (AREA)
Abstract
The invention discloses a method for enhancing the hydrophobic property of a PVDF hollow fiber membrane, which comprises the following steps: 1) dissolving the PVDF/PVC composite material doped with the nano graphite by using a film casting agent to prepare a modified solution; 2) performing surface pretreatment on a PVDF hollow fiber membrane in polyethylene glycol; 3) taking out the PVDF hollow fiber membrane obtained in the step 2), putting the PVDF hollow fiber membrane into the modified solution obtained in the step 1), and then sequentially carrying out solidification, washing, airing and drying to obtain the surface modified PVDF hollow fiber membrane. According to the method, the PVDF hollow fiber membrane is subjected to surface pretreatment firstly, so that the PVDF/PVC doped with the nano graphite can be ensured to be uniformly coated on the membrane surface, the dissolving effect of a solvent DMF on the membrane surface can be prevented, a modified solution is prepared by dissolving the PVDF/PVC doped with the nano graphite by using polyethylene glycol, the PVC is compounded with the PVDF, and the doping of the nano graphite is performed, so that the hydrophobic property of the product is remarkably improved, and the water contact angle of the surface of the modified PVDF hollow fiber membrane is improved to 153 from the original 113 degrees.
Description
Technical Field
The invention relates to a method for enhancing the hydrophobic property of a PVDF hollow fiber membrane, belonging to the technical field of membrane material surface modification.
Background
Polyvinylidene fluoride (PVDF) hollow fiber membranes are commonly used in membrane distillation processes. The PVDF hollow fiber membrane has simple and easily-controlled manufacturing process, good thermal and chemical stability, lower surface heat conductivity coefficient, good permeability and high rejection rate. However, the water contact angle of the PVDF hollow fiber membrane surface is 113 degrees +/-1.7 degrees, the hydrophobic property is not high enough, and the phenomenon of wetting or crystallization pollution is easily caused on the surface in the membrane distillation process, so that the separation effect and the membrane flux are reduced. In order to reduce membrane wetting and membrane fouling, it is necessary to modify the membrane surface to improve the hydrophobic properties.
In the prior art, some reports about hydrophobic modification of a hollow fiber membrane are provided, for example, application with publication number CN106474941A, which discloses a method for hydrophobic modification of the surface of a polyvinylidene fluoride hollow fiber membrane, comprising 1) preparing a modified solution by using perfluoroalkyl acrylate polymer as a solute and butyl acetate as a solvent; 2) placing the modified solution into a modifying device for water bath heating, immersing the polyvinylidene fluoride hollow fiber membrane to be hydrophobically modified into the modified solution after the modified solution reaches a preset temperature, reacting for a certain time, and taking out; 3) cleaning residual liquid on the surface of the polyvinylidene fluoride hollow fiber membrane filaments by using alcohol and deionized water; and (3) putting the membrane filaments into an oven for drying to obtain the hydrophobic modified polyvinylidene fluoride hollow fiber membrane. The application with the publication number of CN105854636A discloses a method for preparing a high-hydrophobicity polyvinylidene fluoride hollow fiber membrane, which comprises the steps of preparing a polyvinylidene fluoride (PVDF) casting solution, spinning a polyvinylidene fluoride hollow fiber membrane, curing to form a membrane and performing hydrophobic modification on the polyvinylidene fluoride membrane to obtain a finished product, wherein the PVDF hydrophobic membrane has good performances of PVDF and good anti-wettability, has good gas flux, is greatly improved in gas flux, mass transfer coefficient and the like compared with the existing hydrophobic membrane material, and is simple in preparation process, low in cost and easy to realize large-scale production. Application with publication number CN107899435A discloses a preparation method of a polyvinylidene fluoride hydrophobic hollow fiber membrane, which comprises the following raw materials in percentage by mass: 25-45% of polyvinylidene fluoride, 20-60% of nano particles and 15-35% of diluent, wherein the sum of the raw materials is 100%; uniformly mixing the weighed nano particles and the diluent, adding the weighed polyvinylidene fluoride, and uniformly mixing again to obtain casting film powder; melting the obtained cast film powder by using an extruder and extruding the molten cast film powder through a spinning nozzle to obtain fiber film filaments, cooling the obtained fiber film filaments through a gel bath to obtain a hollow fiber film coarse body, wherein the dry spinning distance of the spinning nozzle is 2-30 cm; and removing the nano particles and the diluent in the rough body of the obtained hollow fiber membrane to obtain the polyvinylidene fluoride hydrophobic hollow fiber membrane.
Although the hydrophobicity of the hollow fiber membrane is improved to different degrees, the above reports do not relate to the hydrophobic modification of the PVDF hollow fiber membrane surface by coating the nano graphite doped PVDF/PVC coating layer. And has the defects of high operation difficulty, more required auxiliaries, poor controllability and the like.
Disclosure of Invention
The invention provides a method for enhancing the hydrophobic property of a PVDF hollow fiber membrane, wherein a nano-graphite doped PVDF/PVC coating layer is coated on the surface of the PVDF hollow fiber membrane for hydrophobic modification, the water contact angle of the surface of the modified PVDF hollow fiber membrane is increased to 153 ℃ from the original 113 ℃, the operation is simple and easy to control, the required auxiliary agent is less, the cost is low, and the progress is very obvious.
In order to solve the technical problems, the technical scheme adopted by the invention is as follows:
a method for enhancing the hydrophobic property of a PVDF hollow fiber membrane comprises the following steps:
1) dissolving the PVDF/PVC composite material doped with the nano graphite by using a film casting agent to prepare a modified solution;
2) performing surface pretreatment on a PVDF hollow fiber membrane in polyethylene glycol;
3) taking out the PVDF hollow fiber membrane obtained in the step 2), putting the PVDF hollow fiber membrane into the modified solution obtained in the step 1), and then sequentially carrying out solidification, washing, airing and drying to obtain the surface modified PVDF hollow fiber membrane.
The PVDF is polyvinylidene fluoride, and the PVC is polyvinyl chloride.
The surface water contact angle of the modified PVDF hollow fiber membrane is improved to 153 degrees from the original 113 degrees.
The applicant finds that the hydrophobicity of the PVC and the PVDF can be improved by compounding the PVC and the PVDF, and the hydrophobicity of the surface of the membrane can be further improved by doping the nano graphite and the doped rough surface; in the step 2), the PVDF hollow fiber membrane is subjected to surface pretreatment in polyethylene glycol, so that the PVDF/PVC doped with the nano graphite can be uniformly coated on the membrane surface, and the dissolution of a solvent DMF (dimethyl formamide) on the membrane surface can be prevented.
In order to ensure the modification effect, it is preferable that the mold casting agent is a mixture of polyethylene glycol and Dimethylformamide (DMF) in step 1).
Further preferably, in the step 1), the mass content of the polyethylene glycol in the casting film agent is 20-80%. The polyethylene glycol can relieve the solubility of PVDF and PVC in DMF, and the addition of a proper amount of polyethylene glycol can reduce the dissolution damage effect of the casting film agent on the surface of the PVDF hollow fiber film during coating modification.
The membrane surface pretreatment by adopting the polyethylene glycol can ensure that the PVDF/PVC doped with the nano graphite is uniformly coated on the membrane surface and can prevent the solvent DMF from dissolving the membrane surface.
In this application, the percentages are not specifically mentioned.
In order to further ensure the modification effect of the hydrophobic property and the comprehensive performance of the obtained material, in the step 1), the mass ratio of PVDF to PVC in the PVDF/PVC composite material is 90: 10-75: 25, preferably 85: 15-80: 20, and the mass content of the nano graphite in the PVDF/PVC composite material is 0.1-5%, preferably 0.5-1.5%. The addition of PVC in a special proportion not only improves the hydrophobic property of PVDF, but also reduces the material cost.
In order to ensure the stability of the casting agent, in the step 1), the obtained modified solution is stored at a constant temperature of 40 +/-5 ℃.
In order to improve the pretreatment effect and further improve the hydrophobic modification effect, in the step 2), the mass content of DMF in the polyethylene glycol is 20-80%.
In the step 3), when the hollow fiber membrane is kept still and immersed in the membrane casting solution for coating, the coating thickness is controlled by controlling the coating time, and the preferred dip-coating time is 10 s-30 min, and more preferably 5-10 min. The dip coating temperature is 40 +/-5 ℃.
In order to ensure the firmness of the coating layer, the coated hollow fiber membrane needs to be solidified in a cold water bath, and in the step 3), the solidification is carried out in the cold water bath, preferably, the temperature of the cold water bath is 10-35 ℃, and the solidification time is 0.5-10 h, more preferably 0.5-1.5 h.
In the step 3), washing is firstly washed by absolute ethyl alcohol and then by pure water; airing is carried out under natural conditions; in order to completely volatilize the solvent on the surface of the membrane, the coated hollow fiber membrane needs to be dried in an oven, preferably, the drying is carried out for 0.5 to 10 hours at the temperature of between 45 and 80 ℃ under the vacuum condition.
The prior art is referred to in the art for techniques not mentioned in the present invention.
The invention discloses a method for enhancing the hydrophobic property of a PVDF hollow fiber membrane, which is characterized in that polyethylene glycol is used for dissolving PVDF/PVC doped with nano graphite to prepare a modified solution, the hydrophobicity of the PVDF and the PVC can be improved by compounding the PVC and the PVDF, and the hydrophobic property of the surface of the membrane is further improved by simultaneously utilizing the hydrophobicity of the PVDF and a doped rough surface when the nano graphite is doped; the PVDF hollow fiber membrane is firstly subjected to surface pretreatment, so that the PVDF/PVC doped with the nano graphite can be uniformly coated on the surface of the membrane, and the dissolving action of a solvent DMF (dimethyl formamide) on the surface of the membrane can be prevented; the water contact angle of the surface of the modified PVDF hollow fiber membrane is improved to 153 degrees from the original 113 degrees, and the progress is very obvious.
Drawings
FIG. 1 is a contact angle of the modified PVDF hollow fiber membrane obtained in example 1;
FIG. 2 is a scanning electron micrograph of PVDF hollow fiber membranes before and after modification in example 1 (a, b.c are before modification, g, h, i are after modification);
FIG. 3 is a graph comparing permeation flux of PVDF hollow fiber membranes before and after modification in example 2 (■ before modification, ● after modification);
FIG. 4 is an SEM image of the membrane surface of a PVDF hollow fiber membrane before and after modification in example 2 (a-unmodified, b-modified);
FIG. 5 is a contact angle of the modified PVDF hollow fiber membrane obtained in example 3;
FIG. 6 is a scanning electron micrograph of PVDF hollow fiber membranes before and after modification in example 3 (a, b.c before modification, d, e, f after modification);
Detailed Description
In order to better understand the present invention, the following examples are further provided to illustrate the present invention, but the present invention is not limited to the following examples.
Example 1
Preparing a modified casting film solution:
dissolving a PVDF/PVC composite material doped with 1 wt% of nano graphite (XFQ022, Jiangsu Xiancheng nano material science and technology limited) by using polyethylene glycol 200 (analytically pure, national medicine group chemical reagent limited) containing 20 wt% of DMF (analytically pure, Tianjin City Mao chemical reagent factory) to obtain a modified casting film solution, and standing the modified casting film solution at 40 ℃, wherein the mass ratio of PVDF to PVC is 85:15, (PVC + PVDF)/DMF is 4%, PVDF is FR904PVDF, analytically pure, Dongguan Yang polymer materials limited, PVC is P107108PVC, analytically pure, and Aladdin reagent limited.
Modifying a PVDF hollow fiber membrane:
soaking the PVDF hollow fiber membrane in polyethylene glycol 200 containing 30% DMF (dimethyl formamide) for 10min at normal temperature for pretreatment, taking out and soaking in a modified casting solution at the temperature of 40 ℃, completing coating after 10min, taking out and evaporating in the air for 10s, then placing in a cold water bath at the temperature of 25 ℃ for 30min for solidification, taking out and sequentially washing with absolute ethyl alcohol and purified water, naturally airing, and then placing in a vacuum oven for baking for 8h at the temperature of 60 ℃ to obtain the surface modified PVDF hollow fiber membrane.
As shown in fig. 1, the contact angle of the hollow fiber membrane coated with the nano graphite doped PVDF/PVC modified is 153 °, so as to achieve super-hydrophobic performance; as shown in FIG. 2, a scanning electron microscope image shows that the modified PVDF hollow fiber membrane has more obvious micro-nano microsphere level on the surface and increased surface roughness.
Example 2
Comparing the membrane flux and the membrane pollution before and after modification of the hollow fiber membrane:
NaCl saturated at 333K is used as feed liquid, the flow rate of the feed liquid is 40L/h, and the gas sweeping speed is 0.84m3The condensation temperature is 283K, the feed liquid temperature is 333K, the component filling factor is 32 percent, and the permeation flux of the process of treating high-concentration brine by air sweeping type membrane distillation before and after the modification of the PVDF hollow fiber membrane is compared. As a result, as shown in fig. 3, the permeation flux of the modified PVDF hollow fiber membrane (obtained in example 1) decreased by less than 10% after 300min, while the permeation flux of the unmodified PVDF hollow fiber membrane decreased by about 80%. FIGS. 4(a) and (b) are scanning electron microscope images of the PVDF hollow fiber membrane before and after modification, respectively. As shown in fig. 4, after 300min, the unmodified film surface was completely covered with NaCl crystals, while the modified film surface had only a few irregular powder crystals. The results show that the modified hollow modified membrane has super-hydrophobic property, is not easy to wet, the pollution degree of the membrane is obviously slowed down, and the flux of the membrane is relatively stable.
Example 3
Preparing a modified casting film solution:
dissolving PVDF/PVC composite material doped with 2.5 wt% of nano graphite by using 40 wt% of DMF (dimethyl formamide) polyethylene glycol to obtain a modified casting film solution, and standing the modified casting film solution at 40 ℃, wherein the mass ratio of PVDF to PVC is 90:10, and the mass ratio of PVC + PVDF/DMF is 2%. (the specifications and sources of the reagents are the same as those in example 1)
Modifying a PVDF hollow fiber membrane:
soaking the PVDF hollow fiber membrane in polyethylene glycol 200 containing 30% DMF at normal temperature for 10min, taking out, soaking in a modified casting solution at 40 ℃, coating after 10min, taking out, evaporating for 10s in air, then placing in a cold water bath at 25 ℃ for solidifying for 30min, taking out, sequentially washing with absolute ethyl alcohol and purified water, naturally drying, and then placing in a vacuum oven for baking for 8h at 60 ℃ to obtain the surface modified PVDF hollow fiber membrane.
As shown in fig. 5, the contact angle of the hollow fiber membrane coated with the nano-graphite doped PVDF/PVC modification is 151 °, so that super-hydrophobic performance is achieved; as shown in fig. 6, a scanning electron microscope image shows that the roughness of the surface of the modified PVDF hollow fiber membrane is obviously increased, but due to the reduction of the PVC content in PVDF/PVC and the increase of the doped amount of nano-graphite, the nano-graphite slightly agglomerates in the coating layer, so that the surface appearance of the coated membrane is uneven, a layered structure appears, the nano-microsphere layers are not obvious, and the hydrophobic effect is slightly reduced compared with that of example 1.
Claims (10)
1. A method for enhancing the hydrophobic property of a PVDF hollow fiber membrane is characterized in that: the method comprises the following steps:
1) dissolving the PVDF/PVC composite material doped with the nano graphite by using a film casting agent to prepare a modified solution;
2) performing surface pretreatment on a PVDF hollow fiber membrane in polyethylene glycol;
3) taking out the PVDF hollow fiber membrane obtained in the step 2), putting the PVDF hollow fiber membrane into the modified solution obtained in the step 1), and then sequentially carrying out solidification, washing, airing and drying to obtain the surface modified PVDF hollow fiber membrane.
2. The method for enhancing the hydrophobic property of the PVDF hollow fiber membrane of claim 1, wherein: in the step 1), the casting film agent is a mixture of polyethylene glycol and dimethylformamide.
3. The method for enhancing the hydrophobic property of the PVDF hollow fiber membrane of claim 2, wherein: in the step 1), the mass content of the polyethylene glycol in the casting film agent is 20-80%.
4. The method for enhancing the hydrophobic property of the PVDF hollow fiber membrane as set forth in any one of claims 1 to 3, wherein: in the step 1), the mass ratio of PVDF to PVC in the PVDF/PVC composite material is 90: 10-75: 25, and the mass content of the nano graphite in the PVDF/PVC composite material is 0.1-5%.
5. The method for enhancing the hydrophobic property of the PVDF hollow fiber membrane as set forth in any one of claims 1 to 3, wherein: in the step 1), the obtained modified solution is stored at a constant temperature of 40 +/-5 ℃.
6. The method for enhancing the hydrophobic property of the PVDF hollow fiber membrane as set forth in any one of claims 1 to 3, wherein: in the step 2), the polyethylene glycol contains 20-80% by mass of DMF.
7. The method for enhancing the hydrophobic property of the PVDF hollow fiber membrane as set forth in any one of claims 1 to 3, wherein: in the step 3), the dip-coating time is 10 s-30 min, and the dip-coating temperature is 40 +/-5 ℃.
8. The method for enhancing the hydrophobic property of the PVDF hollow fiber membrane as set forth in any one of claims 1 to 3, wherein: in the step 3), the solidification is carried out in a cold water bath, the temperature of the cold water bath is 10-35 ℃, and the solidification time is 0.5-10 h.
9. The method for enhancing the hydrophobic property of the PVDF hollow fiber membrane as set forth in any one of claims 1 to 3, wherein: in the step 3), washing is firstly washed by absolute ethyl alcohol and then by pure water; the drying is carried out under natural conditions.
10. The method for enhancing the hydrophobic property of the PVDF hollow fiber membrane as set forth in any one of claims 1 to 3, wherein: in the step 3), the drying is carried out for 0.5 to 10 hours at the temperature of between 45 and 80 ℃ under the vacuum condition.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011620243.7A CN112808032A (en) | 2020-12-30 | 2020-12-30 | Method for enhancing hydrophobic property of PVDF hollow fiber membrane |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011620243.7A CN112808032A (en) | 2020-12-30 | 2020-12-30 | Method for enhancing hydrophobic property of PVDF hollow fiber membrane |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112808032A true CN112808032A (en) | 2021-05-18 |
Family
ID=75856012
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011620243.7A Pending CN112808032A (en) | 2020-12-30 | 2020-12-30 | Method for enhancing hydrophobic property of PVDF hollow fiber membrane |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112808032A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114984769A (en) * | 2022-06-09 | 2022-09-02 | 万华化学集团股份有限公司 | Fluoropolymer hollow fiber hydrophobic porous membrane and preparation method thereof |
| CN115445246A (en) * | 2022-08-24 | 2022-12-09 | 电子科技大学 | High-performance surface-modified oil-water separation membrane and preparation method and application thereof |
| CN115646217A (en) * | 2022-09-29 | 2023-01-31 | 天津工业大学 | Laminated PFA hollow fiber loose nanofiltration membrane and preparation method thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2017035201A1 (en) * | 2015-08-25 | 2017-03-02 | 3M Innovative Properties Company | Pvdf diffusion membrane for gas and liquid transfer |
| CN107840981A (en) * | 2017-11-08 | 2018-03-27 | 海南师范大学 | A kind of sodium alginate chitosan bilayer edible film, its preparation method and its application |
-
2020
- 2020-12-30 CN CN202011620243.7A patent/CN112808032A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2017035201A1 (en) * | 2015-08-25 | 2017-03-02 | 3M Innovative Properties Company | Pvdf diffusion membrane for gas and liquid transfer |
| CN107840981A (en) * | 2017-11-08 | 2018-03-27 | 海南师范大学 | A kind of sodium alginate chitosan bilayer edible film, its preparation method and its application |
Non-Patent Citations (1)
| Title |
|---|
| 张大帅: "PVDF中空纤维膜表面疏水改性", 《超疏水PVDF/PVC复合膜的制备及其在膜蒸馏海水淡化中的应用》 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114984769A (en) * | 2022-06-09 | 2022-09-02 | 万华化学集团股份有限公司 | Fluoropolymer hollow fiber hydrophobic porous membrane and preparation method thereof |
| CN115445246A (en) * | 2022-08-24 | 2022-12-09 | 电子科技大学 | High-performance surface-modified oil-water separation membrane and preparation method and application thereof |
| CN115445246B (en) * | 2022-08-24 | 2023-10-20 | 电子科技大学 | High-performance surface-modified oil-water separation membrane and preparation method and application thereof |
| CN115646217A (en) * | 2022-09-29 | 2023-01-31 | 天津工业大学 | Laminated PFA hollow fiber loose nanofiltration membrane and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112808032A (en) | Method for enhancing hydrophobic property of PVDF hollow fiber membrane | |
| CN108246125B (en) | High-anti-pollution internal support polyvinylidene fluoride hollow fiber membrane and preparation method thereof | |
| CN104607064A (en) | Method for preparing polyvinylidene fluoride-graphene oxide composite hollow fiber membrane | |
| CN111346522B (en) | Polyvinyl alcohol-ethylene copolymer honeycomb porous membrane and preparation method thereof | |
| WO2021258701A1 (en) | Preparation method of sustainable hydrophilic modified polyvinylidene fluoride hollow membrane | |
| CN110201558B (en) | Large-flux reinforced PVDF unlined ultrafiltration membrane and preparation method thereof | |
| WO2005014151A1 (en) | The preparation method of exo-pressure type poly(vinylidene fluoride) hollow fiber membrane spinned utilizing a immersion-coagulation method and the product thereof | |
| CN105536551B (en) | A kind of preparation method of polymer-based nano composite hyperfiltration membrane | |
| CN103933873B (en) | A kind of self-supporting PVDF homogeneous porous tubular film and preparation method thereof | |
| CN107970789B (en) | Hydrophobic membrane with micro-nano structure surface functional layer and preparation method thereof | |
| CN105032211A (en) | Novel hydrophobic membrane and preparation method thereof | |
| KR20080057637A (en) | Method for manufacturing polyvinylidene fluoride hollow fiber membrane and hollow fiber membrane | |
| JP5983981B2 (en) | Method for producing porous membrane | |
| KR101381080B1 (en) | Double layer hydrophilic hollow fiber membrane and its manufacturing method combined supported layer by Thermally Induced Phase Separation and active layer by Non-solvent Induced Phase Separation | |
| CN108479414B (en) | Hollow fiber polymer membrane, preparation method and application thereof in brine refining | |
| US11766640B2 (en) | Method for preparing block copolymer hollow fiber membrane by melt spinning-stretching and selective swelling | |
| CN107570021B (en) | Hydrophilic polysulfone/silicon dioxide blended hollow fiber membrane and preparation method thereof | |
| KR100850167B1 (en) | PVDF membrane with high porosity and permeation and method for manufacturing the same | |
| KR101443491B1 (en) | Method for preparing hollow fiber membrane and hollow fiber membrane prepared thereby | |
| KR101198646B1 (en) | Manufacturing method of asymmetric porous membrane and asymmetric porous membrane thereby | |
| CN114588792A (en) | Polyvinyl butyral blending enhanced polyvinylidene chloride film and preparation method thereof | |
| CN108218247B (en) | TiO with hierarchical structure morphology2Method for producing thin film | |
| CN111495201A (en) | Method for preparing porous material through indirect thermally induced phase separation | |
| CN113462161B (en) | Silicone rubber composite material with water vapor barrier function and preparation method thereof | |
| CN110721597B (en) | Method for simply preparing porous membrane with excellent connectivity |
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 | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20210518 |
|
| WD01 | Invention patent application deemed withdrawn after publication |