CN115228305A - Janus film and preparation method thereof - Google Patents
Janus film and preparation method thereof Download PDFInfo
- Publication number
- CN115228305A CN115228305A CN202210698771.7A CN202210698771A CN115228305A CN 115228305 A CN115228305 A CN 115228305A CN 202210698771 A CN202210698771 A CN 202210698771A CN 115228305 A CN115228305 A CN 115228305A
- Authority
- CN
- China
- Prior art keywords
- layer
- hydrophobic
- semi
- finished product
- porous 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.)
- Pending
Links
- 238000002360 preparation method Methods 0.000 title abstract description 20
- 230000002209 hydrophobic effect Effects 0.000 claims abstract description 144
- 239000012528 membrane Substances 0.000 claims abstract description 82
- 229920001690 polydopamine Polymers 0.000 claims abstract description 76
- 239000000758 substrate Substances 0.000 claims abstract description 67
- 238000000576 coating method Methods 0.000 claims abstract description 18
- 239000011148 porous material Substances 0.000 claims abstract description 17
- 239000011248 coating agent Substances 0.000 claims abstract description 15
- 229920002981 polyvinylidene fluoride Polymers 0.000 claims description 70
- 239000011265 semifinished product Substances 0.000 claims description 66
- 239000000243 solution Substances 0.000 claims description 62
- 239000002033 PVDF binder Substances 0.000 claims description 50
- VYFYYTLLBUKUHU-UHFFFAOYSA-N dopamine Chemical compound NCCC1=CC=C(O)C(O)=C1 VYFYYTLLBUKUHU-UHFFFAOYSA-N 0.000 claims description 46
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 38
- 238000000034 method Methods 0.000 claims description 29
- FXHOOIRPVKKKFG-UHFFFAOYSA-N N,N-Dimethylacetamide Chemical compound CN(C)C(C)=O FXHOOIRPVKKKFG-UHFFFAOYSA-N 0.000 claims description 25
- 229960003638 dopamine Drugs 0.000 claims description 23
- 238000005345 coagulation Methods 0.000 claims description 22
- 230000015271 coagulation Effects 0.000 claims description 22
- 238000005191 phase separation Methods 0.000 claims description 18
- 239000002904 solvent Substances 0.000 claims description 17
- 238000001035 drying Methods 0.000 claims description 14
- 239000008367 deionised water Substances 0.000 claims description 12
- 229910021641 deionized water Inorganic materials 0.000 claims description 12
- 230000001112 coagulating effect Effects 0.000 claims description 10
- 239000000463 material Substances 0.000 claims description 9
- 239000002390 adhesive tape Substances 0.000 claims description 8
- 239000004745 nonwoven fabric Substances 0.000 claims description 8
- 230000003746 surface roughness Effects 0.000 claims description 8
- 238000004519 manufacturing process Methods 0.000 claims description 4
- 239000004696 Poly ether ether ketone Substances 0.000 claims description 3
- 239000012670 alkaline solution Substances 0.000 claims description 3
- JUPQTSLXMOCDHR-UHFFFAOYSA-N benzene-1,4-diol;bis(4-fluorophenyl)methanone Chemical compound OC1=CC=C(O)C=C1.C1=CC(F)=CC=C1C(=O)C1=CC=C(F)C=C1 JUPQTSLXMOCDHR-UHFFFAOYSA-N 0.000 claims description 3
- 229920002530 polyetherether ketone Polymers 0.000 claims description 3
- 238000002791 soaking Methods 0.000 abstract description 6
- 238000011031 large-scale manufacturing process Methods 0.000 abstract description 3
- 229920001155 polypropylene Polymers 0.000 description 36
- 239000004743 Polypropylene Substances 0.000 description 19
- 239000005871 repellent Substances 0.000 description 16
- 238000000926 separation method Methods 0.000 description 16
- 235000019198 oils Nutrition 0.000 description 13
- 230000008569 process Effects 0.000 description 9
- 239000007983 Tris buffer Substances 0.000 description 8
- LENZDBCJOHFCAS-UHFFFAOYSA-N tris Chemical compound OCC(N)(CO)CO LENZDBCJOHFCAS-UHFFFAOYSA-N 0.000 description 8
- 238000006116 polymerization reaction Methods 0.000 description 6
- -1 polypropylene Polymers 0.000 description 6
- 238000007711 solidification Methods 0.000 description 6
- 230000008023 solidification Effects 0.000 description 6
- 239000000835 fiber Substances 0.000 description 4
- 238000012986 modification Methods 0.000 description 4
- 230000004048 modification Effects 0.000 description 4
- 238000001878 scanning electron micrograph Methods 0.000 description 4
- 238000004090 dissolution Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 238000003756 stirring Methods 0.000 description 3
- 238000012512 characterization method Methods 0.000 description 2
- 238000010168 coupling process Methods 0.000 description 2
- 239000000839 emulsion Substances 0.000 description 2
- 238000005188 flotation Methods 0.000 description 2
- 230000005484 gravity Effects 0.000 description 2
- 230000005660 hydrophilic surface Effects 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 235000019476 oil-water mixture Nutrition 0.000 description 2
- 239000012466 permeate Substances 0.000 description 2
- 239000010865 sewage Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 239000011358 absorbing material Substances 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000004132 cross linking Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000007606 doctor blade method Methods 0.000 description 1
- 238000010041 electrostatic spinning Methods 0.000 description 1
- 238000005189 flocculation Methods 0.000 description 1
- 230000016615 flocculation Effects 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 239000010842 industrial wastewater Substances 0.000 description 1
- 239000007764 o/w emulsion Substances 0.000 description 1
- 238000001782 photodegradation Methods 0.000 description 1
- 239000007762 w/o emulsion Substances 0.000 description 1
- 239000002351 wastewater Substances 0.000 description 1
- 238000004065 wastewater treatment Methods 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
Images
Classifications
-
- 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
- B01D69/12—Composite membranes; Ultra-thin 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
- B01D71/06—Organic material
- B01D71/58—Other polymers having nitrogen in the main chain, with or without oxygen or carbon only
- B01D71/60—Polyamines
-
- 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
- C02F1/40—Devices for separating or removing fatty or oily substances or similar floating material
-
- 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
Abstract
The invention discloses a Janus film and a preparation method thereof, wherein the Janus film comprises a porous substrate layer, a first hydrophobic layer arranged on the porous substrate layer, a second hydrophobic layer stacked on the first hydrophobic layer and a polydopamine layer stacked on the second hydrophobic layer; the porous substrate layer is hydrophobic, and the first hydrophobic layer is partially infiltrated and fixed in the pores of the porous substrate layer. The Janus film comprises a porous substrate layer, a first hydrophobic layer, a second hydrophobic layer and a polydopamine layer, and can be prepared in a coating, soaking and stripping mode, and the preparation process is relatively simple, convenient and efficient. Compared with the traditional scheme, the Janus membrane has the advantages of relatively simple structure, relatively simple and convenient preparation process, commercial availability and suitability for large-scale production.
Description
Technical Field
The invention relates to the field of oil-water separation, in particular to a Janus film and a preparation method thereof.
Background
In recent decades, industrial oily wastewater, sewage discharge and frequent oil leakage problems have posed serious threats to the environment and human health. The traditional oily wastewater treatment methods (such as air flotation, gravity separation, coagulation and the like) are limited by the defects of high operation cost, low separation efficiency and the like, so that the development of a novel efficient and low-cost oil-water separation technology is urgent.
Various techniques such as air flotation, gravity separation, oil-absorbing materials, coagulation and flocculation have been used so far for separating oil/water mixtures, but the running cost is high and the separation efficiency is low, and it is required to develop cost-effective techniques. Membrane-based oil-water separation techniques are simple to manufacture and operate, are highly efficient, are considered to be an advanced oil/water separation technique, but are not effective in treating emulsified oil/water mixtures, particularly where the oil droplet size is less than 20 microns.
In recent years, a great deal of attention has been paid to oil-water separation technology based on a separation membrane, and the technology has great development potential in the aspect of treating industrial wastewater and oily sewage due to the advantages of simplicity, high efficiency and the like. However, in complex oil-water mixtures (such as oil-in-water or water-in-oil emulsion systems), the separation performance of the separation membrane is significantly reduced. At present, depending on the different wetting behavior of the membrane surface for oil and water, a hydrophilic/oleophobic membrane can be used to remove water, while a hydrophobic/lipophilic membrane removes oil from the oil-water mixture. In order to further solve the problem of unidirectional selective permeation of membrane materials to oil or water, researchers develop a novel membrane with asymmetric wettability on two sides, namely a Janus membrane, so that the requirement of separating oil-in-water and water-in-oil emulsions can be met simultaneously only by switching the feeding surface of the membrane [1].
The Janus membrane has extremely high selectivity in the separation process, and the simultaneous separation of oil-in-water and water-in-oil emulsions can be realized through simple feed surface switching. In designing and preparing Janus membrane, it is key to regulate membrane asymmetry. At present, in the aspect of preparation or modification of Janus membrane asymmetry, continuous electrostatic spinning, continuous surface modification, membrane single-side photoinitiated crosslinking or photodegradation and the like are general strategies for constructing Janus membranes with asymmetric wettability [2-6].
However, the prior art needs to introduce a multi-step process in the Janus membrane modification process, which makes the industrial production of the Janus membrane difficult. Therefore, in order to meet the increasing market demand and commercialization demand, it is of practical interest to develop a commercially available Janus membrane that is relatively simple in structure, relatively simple in preparation process.
Reference documents:
[1]I.Cho,K.-W Lee,Morphology of latex particles formed by poly(methyl methacrylate)-seeded emulsion polymerization of styrene,J.Appl.Polym.Sci.30 (1985)1903–1926.
[2]Z.Wang,G.Liu,S.Huang,In Situ Generated Janus Fabrics for the Rapid and Efficient Separation of Oil from Oil-in-Water Emulsions,Angew.Chemie-Int.Ed. 55(2016)14610–14613.
[3]M.B.Wu,H.C.Yang,J.J.Wang,G.P.Wu,Z.K.Xu,Janus Membranes with Opposing Surface Wettability Enabling Oil-to-Water and Water-to-Oil Emulsification, ACS Appl.Mater.Interfaces.9(2017)5062–5066.
[4]Y.P.An,J.Yang,H.C.Yang,M.B.Wu,Z.K.Xu,Janus Membranes with Charged Carbon Nanotube Coatings for Deemulsification and Separation of Oil-in-Water Emulsions,ACS Appl.Mater.Interfaces.10(2018)9832–9840.
[5]Y.Lin,M.S.Salem,L.Zhang,Q.Shen,A.H.El-shazly,N.Nady,H. Matsuyama,Development of Janus membrane with controllable asymmetric wettability for highly-efficient oil/water emulsions separation,J.Memb.Sci.606 (2020)118141.
[6]J.H.Zuo,Y.H.Gu,C.Wei,X.Yan,Y.Chen,W.Z.Lang,Janus polyvinylidene fluoride membranes fabricated with thermally induced phase separation and spray-coating technique for the separations of both W/O and O/W emulsions,J.Memb.Sci.595(2020)117475.
disclosure of Invention
Based on this, there is a need for a Janus film and a method for preparing the same that can solve the above problems.
A Janus membrane capable of efficiently separating oil and water comprises a porous base layer, a first hydrophobic layer arranged on the porous base layer, a second hydrophobic layer stacked on the first hydrophobic layer and a polydopamine layer stacked on the second hydrophobic layer;
the porous substrate layer is hydrophobic, and the first hydrophobic layer is partially infiltrated and fixed in the pores of the porous substrate layer.
In one embodiment, a side of the second hydrophobic layer remote from the first hydrophobic layer is provided with a relief pattern for increasing surface roughness.
In one embodiment, the porous substrate layer is a non-woven fabric, the porosity of the porous substrate layer is 70% to 95%, the pore size of the pores of the porous substrate layer is 15 μm to 85 μm, and the thickness of the porous substrate layer is 0.2mm to 0.8mm.
In one embodiment, the first hydrophobic layer and the second hydrophobic layer are made of the same material, and the material of the first hydrophobic layer is PVDF, PSU, PES, CA, PVC, PAN, PVA, PEEK or PA;
the thickness of the first hydrophobic layer is 8-12 microns, the thickness of the second hydrophobic layer is 6.5-10 microns, and the thickness of the polydopamine layer is 1-5 microns.
The preparation method of the Janus membrane comprises the following steps:
coating a first hydrophobic organic solution on a porous substrate, immersing the porous substrate in a first coagulating bath to complete non-solvent induced phase separation and perform first solidification, and drying to obtain a first semi-finished product, wherein the first semi-finished product comprises a porous substrate layer and a first hydrophobic layer arranged on the porous substrate layer, the first hydrophobic layer partially permeates into and is fixed in holes of the porous substrate layer, and the mass concentration of the first hydrophobic organic solution is 10-15%;
coating a second hydrophobic organic solution on the first hydrophobic layer of the first semi-finished product to obtain a second semi-finished product, then placing the second semi-finished product in an environment with the relative humidity of 75-85% and the room temperature for 3-10 min to complete steam-induced phase separation, then immersing the second semi-finished product into a second coagulating bath to carry out secondary solidification, so that a second hydrophobic layer is formed on the first hydrophobic layer, and drying to obtain a third semi-finished product, wherein the mass concentration of the second hydrophobic organic solution is 8-12%, and the mass concentration of the second hydrophobic organic solution is smaller than that of the first hydrophobic organic solution;
immersing the third semi-finished product into a dopamine solution, and immersing for 8-16 h at 55-65 ℃ to form a polydopamine membrane on the outer surface of the third semi-finished product, thereby obtaining a fourth semi-finished product, wherein the dopamine solution is an alkaline solution, and the mass concentration of the dopamine solution is 1 mg/mL-5 mg/mL; and
and removing the polydopamine film covered on the porous substrate layer in the fourth semi-finished product, so as to expose the porous substrate layer, wherein the polydopamine film covered on the second hydrophobic layer is a polydopamine layer, and thus the required Janus film is obtained.
In one embodiment, the operation of coating a second hydrophobic organic solution on the first hydrophobic layer of the first semi-finished product to obtain a second semi-finished product, then placing the second semi-finished product in an environment with a relative humidity of 75% to 85% and a room temperature for 3min to 10min to complete steam-induced phase separation, then immersing the second semi-finished product in a second coagulation bath for second curing to form a second hydrophobic layer on the first hydrophobic layer, and drying to obtain a third semi-finished product is as follows:
coating a second hydrophobic organic solution on the first hydrophobic layer of the first semi-finished product, fixing a gasket with concave-convex patterns on the surface on the second hydrophobic organic solution to obtain a second semi-finished product, then placing the second semi-finished product in an environment with the relative humidity of 75-85% and the room temperature for 3-10 min to complete steam-induced phase separation, then immersing the second semi-finished product in a second solidification bath, removing the gasket after 40-90 s, continuing to perform second solidification to form a second hydrophobic layer on the first hydrophobic layer, forming concave-convex patterns corresponding to the gasket with concave-convex patterns on one surface of the second hydrophobic layer far away from the first hydrophobic layer, and drying to obtain a third semi-finished product.
In one embodiment, the shims with the embossment are diamond-grid shims.
In one embodiment, the solvent of the first hydrophobic organic solution is N, N-dimethylacetamide;
the time of the first curing is 30-50 min, and the first coagulation bath is a deionized water coagulation bath.
In one embodiment, the solvent of the second hydrophobic organic solution is N, N-dimethylacetamide;
the time of the second curing is 40-50 min, and the second coagulation bath is a deionized water coagulation bath.
In one embodiment, the removing of the polydopamine film covering the porous substrate layer in the fourth semi-finished product is:
peeling the polydopamine film covering the porous substrate layer in the fourth semi-finished product with an adhesive tape.
The Janus film comprises a porous substrate layer, a first hydrophobic layer, a second hydrophobic layer and a polydopamine layer, and can be prepared in a coating, soaking and stripping mode, and the preparation process is relatively simple, convenient and efficient.
Compared with the traditional scheme, the Janus membrane has the advantages of relatively simple structure, relatively simple and convenient preparation process, commercial availability and suitability for large-scale production.
In addition, the preparation method of the Janus membrane prepares a first hydrophobic layer and a second hydrophobic layer on the porous substrate through the coupling application of a non-solvent induced phase separation (NIPS) method and a steam induced phase separation (VIPS) method; and then in a weakly alkaline environment, modifying the surfaces of the porous substrate layer and the second hydrophobic layer with a polydopamine membrane with excellent hydrophilicity through Dopamine (DA) self-polymerization reaction, finally removing the polydopamine membrane covered on the porous substrate layer in the fourth semi-finished product, and reserving the polydopamine layer covered on the second hydrophobic layer, thereby preparing the Janus membrane with asymmetric water wettability (the polydopamine layer is a hydrophilic side, and the porous substrate layer is a hydrophobic side).
Furthermore, by combining an interval imprinting method, concave-convex patterns corresponding to the pads with concave-convex patterns are formed on one surface, far away from the first hydrophobic layer, of the second hydrophobic layer, so that the effective surface area and the surface roughness of the second hydrophobic layer are increased, and the area of the polydopamine layer and the bonding strength of the second hydrophobic layer and the polydopamine layer are improved.
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, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without any creative effort.
Wherein:
fig. 1 is a schematic structural diagram of a Janus membrane according to an embodiment.
Fig. 2 is a flow chart of a method of making a Janus membrane as shown in fig. 1.
FIG. 3 is an SEM image of the PP side of the PVDF membrane (PVDF @ PP) prepared in example 1.
FIG. 4 is an SEM image of the PDA/PVDF side of the PDA/PVDF @ PP/PDA film prepared in example 1, and the inset is a water contact angle test result chart.
FIG. 5 is an SEM image of the PP side of the PDA/PVDF @ PP/PDA film sheet prepared in example 1.
Fig. 6 is an SEM image of the PP side of the Janus membrane prepared in example 1, with the inset showing the water contact angle test results.
Fig. 7 is a graph showing the results of the PDA side water contact angle test of the Janus film prepared in example 1.
Fig. 8 is a graph showing the results of the PDA side oil contact angle test of the Janus film prepared in example 1.
FIG. 9 is a graph of the results of the PVDF @ PP side water contact angle test of the Janus film prepared in example 1.
FIG. 10 is a graph of the results of the water contact angle test in the oil environment on the PVDF @ PP side of the Janus film prepared in example 1.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. 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.
Referring to fig. 1, the present invention further discloses an embodiment of a Janus membrane, which includes a porous substrate layer 10, a first water-repellent layer 20 disposed on the porous substrate layer 10, a second water-repellent layer 30 stacked on the first water-repellent layer 20, and a polydopamine layer 40 stacked on the second water-repellent layer 30.
The porous substrate layer 10 is hydrophobic, and the first water-repellent layer 20 partially penetrates into and is fixed in the pores of the porous substrate layer 10.
The Janus film comprises a hole substrate layer 10, a first water-repellent layer 20, a second water-repellent layer 30 and a polydopamine layer 40, and can be prepared in a coating, soaking and stripping mode, and the preparation process is relatively simple and efficient.
Compared with the traditional scheme, the Janus membrane has the advantages of relatively simple structure, relatively simple and convenient preparation process, commercial availability and suitability for large-scale production.
Preferably, in this embodiment, the surface of the second water-repellent layer 30 remote from the first water-repellent layer 20 is provided with a concave-convex pattern 32 for increasing surface roughness.
The concave-convex pattern 32 for increasing the surface roughness is arranged on one surface, far away from the first hydrophobic layer 20, of the second hydrophobic layer 30, so that the effective surface area and the surface roughness of the second hydrophobic layer 20 are increased, and the area of the polydopamine layer 40 and the bonding strength of the second hydrophobic layer 30 and the polydopamine layer 40 are improved.
Preferably, the porous substrate layer 10 is a nonwoven fabric, the porosity of the porous substrate layer 10 is 70% to 95%, the pore size of the pores of the porous substrate layer 10 is 15 μm to 85 μm, and the thickness of the porous substrate layer 10 is 0.2mm to 0.8mm.
Specifically, in the present embodiment, the porous base layer 10 is a polypropylene (PP) nonwoven fabric having a thickness of 0.4mm, a porosity of 80%, and a pore size of 20 μm.
Preferably, the material of the first water-repellent layer 20 and the material of the second water-repellent layer 30 are the same, and the material of the first water-repellent layer 20 is PVDF, PSU, PES, CA, PVC, PAN, PVA, PEEK or PA.
It is particularly preferred that both the first water-repellent layer 20 and the second water-repellent layer 30 are PVDF (polyvinylidene fluoride). PVDF (polyvinylidene fluoride) has excellent mechanical strength, strong chemical stability, and an industrially mature preparation process.
Preferably, the first water-repellent layer 20 has a thickness of 8 to 12 μm, the second water-repellent layer 30 has a thickness of 6.5 to 10 μm, and the polydopamine layer 40 has a thickness of 1 to 5 μm.
With reference to fig. 2, the present invention also discloses a preparation method of the Janus membrane according to an embodiment, including the following steps:
s10, coating the first hydrophobic organic solution on a porous substrate, immersing the porous substrate into a first coagulating bath to complete non-solvent induced phase separation, carrying out primary curing, and drying to obtain a first semi-finished product.
The first semi-finished product comprises a porous substrate layer 10 and a first hydrophobic layer 20 arranged on the porous substrate layer 10, wherein the first hydrophobic layer 20 partially permeates into and is fixed in holes of the porous substrate layer 10, and the mass concentration of the first hydrophobic organic solution is 10% -15%.
In this embodiment, the operation of coating the first hydrophobic organic solution on the porous substrate may be performed by a doctor blade coating machine.
Preferably, the porous substrate layer 10 is a nonwoven fabric, the porosity of the porous substrate layer 10 is 70% to 95%, the pore size of the pores of the porous substrate layer 10 is 15 μm to 85 μm, and the thickness of the porous substrate layer 10 is 0.2 μm to 0.8mm.
Specifically, in the present embodiment, the porous base layer 10 is a polypropylene (PP) nonwoven fabric having a thickness of 0.4mm, a porosity of 80%, and a pore size of 20 μm.
Preferably, in this embodiment, the solvent of the first hydrophobic organic solution is N, N-dimethylacetamide (DMAc).
In the present embodiment, the time for the first curing is preferably 30 to 50min, and the first coagulation bath is a deionized water coagulation bath.
S20, coating a second hydrophobic organic solution on the first hydrophobic layer 20 of the first semi-finished product to obtain a second semi-finished product, then placing the second semi-finished product in an environment with the relative humidity of 75% -85% and the room temperature for 3-10 min to complete steam-induced phase separation, then immersing the second semi-finished product into a second coagulating bath to carry out second curing, so that a second hydrophobic layer is formed on the first hydrophobic layer 20, and drying to obtain a third semi-finished product.
Wherein the mass concentration of the second hydrophobic organic solution is 8-12%, and the mass concentration of the second hydrophobic organic solution is less than that of the first hydrophobic organic solution.
Preferably, in this embodiment, the solvent of the second hydrophobic organic solution is N, N-dimethylacetamide.
In the present embodiment, the time for the second curing is preferably 40 to 50min, and the second coagulation bath is a deionized water coagulation bath.
Specifically, in the present embodiment, S30 is: coating a second hydrophobic organic solution on the first hydrophobic layer 20 of the first semi-finished product, fixing a gasket with concave-convex patterns on the surface of the gasket on the second hydrophobic organic solution to obtain a second semi-finished product, then placing the second semi-finished product in an environment with the relative humidity of 75-85% and the room temperature for 3-10 min to complete steam-induced phase separation, then immersing the second semi-finished product in a second solidification bath, removing the gasket after 40-90 s, continuing to perform second-time solidification to form a second hydrophobic layer on the first hydrophobic layer 20, forming concave-convex patterns corresponding to the gasket with concave-convex patterns on one surface of the second hydrophobic layer 30 far away from the first hydrophobic layer 20, and drying to obtain a third semi-finished product.
And by combining an interval imprinting method, a concave-convex pattern corresponding to the gasket with the concave-convex pattern is formed on one surface of the second hydrophobic layer, which is far away from the first hydrophobic layer, so that the effective surface area and the surface roughness of the second hydrophobic layer are increased, and the area of the polydopamine layer and the bonding strength of the second hydrophobic layer and the polydopamine layer are improved.
Preferably, the shim with the embossment is a diamond-shaped lattice shim.
And S30, soaking the third semi-finished product in a dopamine solution for 8-16 h at 55-65 ℃, so that a polydopamine film is formed on the outer surface of the third semi-finished product, and thus a fourth semi-finished product is obtained.
Wherein the dopamine solution is an alkaline solution, and the mass concentration of the dopamine solution is 1 mg/mL-5 mg/mL.
Preferably, the pH of the dopamine solution is 7.0 to 9.0.
Specifically, in the present embodiment, the dopamine solution is a Tris buffer solution of dopamine having a pH of 8.0 to 9.0, wherein the concentration of Tris is 0.01mol/L to 0.1mol/L.
And S40, removing the polydopamine film covered on the porous substrate layer 10 in the fourth semi-finished product so as to expose the porous substrate layer 10, wherein the polydopamine film covered on the second hydrophobic layer 30 is the polydopamine layer 40, and thus the needed Janus film is obtained.
Preferably, the operation of removing the polydopamine film covering the porous substrate layer 10 in the fourth semi-finished product is: the polydopamine film in the fourth semi-finished product, which was covered on the porous substrate layer 10, was peeled off with an adhesive tape.
In particular, the tape may be 3M
Fiber adhesive tape.
In addition, the preparation method of the Janus membrane selects PVDF (PVDF) with excellent mechanical strength, strong chemical stability and industrially mature preparation process and combines polypropylene PP to provide hydrophobicity and stability of the Jnaus membrane. First and second PVDF hydrophobic membranes are prepared on a porous substrate by coupled application of non-solvent induced phase separation (NIPS) and Vapor Induced Phase Separation (VIPS) methods. And then modifying the surfaces of the porous substrate layer and the second PVDF hydrophobic membrane with a polydopamine membrane with excellent hydrophilicity through Dopamine (DA) self-polymerization reaction in a weakly alkaline environment, finally removing the polydopamine membrane covering the porous substrate layer 10 in the fourth semi-finished product, and reserving the polydopamine layer covering the second hydrophobic layer, so that the Janus membrane with asymmetric water wettability is prepared (the polydopamine layer is a hydrophilic side, and the porous substrate layer is a hydrophobic side).
The following are specific examples.
Example 1
A12 wt% DMAc solution of PVDF and a 10wt% DMAc solution of PVDF were prepared, respectively. The specific method comprises the following steps: PVDF was dissolved in N, N-dimethylacetamide (DMAc) solvent under vigorous stirring and heated at 65 ℃ until complete dissolution of PVDF.
A12 wt% DMAc solution of PVDF was poured onto a polypropylene (PP) nonwoven having a thickness of 0.4mm, a porosity of 80% and a pore size of 20 μm, and the coating process was completed using a knife coater, with a wet film thickness of 230 μm, immediately followed by immersion in a coagulation bath of deionized water to complete the non-solvent induced phase separation (NIPS) process. The soaked film was left to stand for 45 minutes to form a cured film, and then the film was dried at room temperature for 48 hours to form a first PVDF layer.
A 10wt% solution of PVDF in DMAc was then poured onto the first PVDF layer at the same thickness, immediately followed by fixing a diamond-shaped corrugated shim on the cast second PVDF layer and left together in an 80% Relative Humidity (RH), room temperature environment for 5 minutes to complete the VIPS process. Finally, the membrane together with the gasket was immersed in a coagulation bath of deionized water, and the gasket was removed after 1 minute. Curing in a coagulating bath for 1 hour to form a film, and continuously drying at room temperature for 48 hours to obtain the PVDF membrane with a rough surface.
Subsequently, the prepared PVDF membrane is immersed in a Tris buffer solution (Tris concentration is 0.01mol/L, pH = 8.5) containing 2mg/mL of Dopamine (DA), soaked for 12h under the condition of 60 ℃, and a hydrophilic polydopamine membrane is modified on the surface of the PVDF membrane through self-polymerization reaction, so that the PDA/PVDF @ PP/PDA membrane is obtained.
Finally pass through 3M
The polydopamine membrane on the PP side is stripped by the fiber adhesive tape, the hydrophobic PVDF @ PP is exposed, and the Janus membrane with asymmetric wettability is prepared (the PDA is the hydrophilic side, and the PVDF @ PP is the hydrophilic side)The hydrophobic side).
Example 2
A10 wt% DMAc solution of PVDF and an 8wt% DMAc solution of PVDF were prepared, respectively. The specific method comprises the following steps: PVDF was dissolved in N, N-dimethylacetamide (DMAc) solvent under vigorous stirring and heated at 65 ℃ until complete dissolution of PVDF.
A10 wt% DMAc solution of PVDF was poured on a polypropylene (PP) non-woven fabric having a thickness of 0.4mm, a porosity of 80% and a pore size of 20 μm, and the coating process was completed using a knife coater, having a wet film thickness of 230 μm, and immediately thereafter immersed in a coagulation bath of deionized water to complete a non-solvent induced phase separation (NIPS) process. The soaked film was left to stand for 45 minutes to form a cured film, and then the film was dried at room temperature for 48 hours to form a first PVDF layer.
An 8wt% solution of PVDF in DMAc was then poured onto the first PVDF layer at the same thickness, immediately followed by fixing a diamond-shaped corrugated shim on the cast second PVDF layer and left together in an 80% Relative Humidity (RH), room temperature environment for 5 minutes to complete the VIPS process. Finally, the membrane together with the gasket was immersed in a coagulation bath of deionized water, and the gasket was removed after 1 minute. Curing in a coagulating bath for 1 hour to form a film, and continuously drying at room temperature for 48 hours to obtain the PVDF membrane with a rough surface.
Subsequently, the prepared PVDF membrane is immersed in a Tris buffer solution (Tris concentration is 0.01mol/L, pH = 8.5) containing 1mg/mL of Dopamine (DA), soaked for 16h under the condition of 65 ℃, and a hydrophilic polydopamine membrane is modified on the surface of the PVDF membrane through self-polymerization reaction, so that the PDA/PVDF @ PP/PDA membrane is obtained.
Finally pass through 3M
The polydopamine membrane on the PP side is peeled off by the fiber adhesive tape, and the hydrophobic PVDF @ PP is exposed, so that the Janus membrane with asymmetric wettability is prepared (the PDA is a hydrophilic side, and the PVDF @ PP is a hydrophobic side).
Example 3
A15 wt% DMAc solution of PVDF and a 12wt% DMAc solution of PVDF were prepared, respectively. The specific method comprises the following steps: PVDF was dissolved in N, N-dimethylacetamide (DMAc) solvent under vigorous stirring and heated at 65 ℃ until complete dissolution of PVDF.
A15 wt% DMAc solution of PVDF was poured on a polypropylene (PP) non-woven fabric having a thickness of 0.4mm, a porosity of 80% and a pore size of 20 μm, and the coating process was completed using a knife coater, having a wet film thickness of 230 μm, and immediately thereafter immersed in a coagulation bath of deionized water to complete a non-solvent induced phase separation (NIPS) process. The soaked film was left to stand for 45 minutes to form a cured film, and then the film was dried at room temperature for 48 hours to form a first PVDF layer.
A 12wt% solution of PVDF in DMAc was then poured onto the first PVDF layer at the same thickness, immediately followed by fixing a diamond-shaped corrugated shim on the cast second PVDF layer and left together in an 80% Relative Humidity (RH), room temperature environment for 5 minutes to complete the VIPS process. Finally, the membrane together with the gasket was immersed in a coagulation bath of deionized water, and the gasket was removed after 1 minute. Solidifying in a coagulating bath for 1 hour to form a film, and continuously drying at room temperature for 48 hours to obtain the PVDF film with rough surface.
Subsequently, the prepared PVDF membrane was immersed in a Tris buffer solution containing 5mg/mL Dopamine (DA) (Tris concentration 0.01mol/L, pH = 8.5) at 55 ℃ for 8 hours, and a hydrophilic polydopamine membrane was modified on the surface of the PVDF membrane by auto-polymerization to obtain a PDA/PVDF @ pp/PDA membrane.
Finally pass through 3M
The polydopamine membrane on the PP side is peeled off by the fiber adhesive tape, and the hydrophobic PVDF @ PP is exposed, so that the Janus membrane with asymmetric wettability is prepared (the PDA is a hydrophilic side, and the PVDF @ PP is a hydrophobic side).
Test example
Microstructural characterisation
The PVDF film (PVDF @ PP), PDA/PVDF @ PP/PDA film and Janus film obtained in example 1 were observed in a microscope to obtain FIGS. 3 to 6.
With reference to fig. 3, from the SEM characterization results, the pvdf @ pp hydrophobic membrane prepared by the coupling method has a hierarchical surface structure with macro-corrugation and micro-rough spherulite crystals, and the surface structure prepared by the method effectively improves the specific surface area and the surface roughness of the material.
Under mild conditions, a layer of polydopamine is successfully modified on the surface of the PVDF hydrophobic membrane by a dopamine self-polymerization method. SEM pictures show that polydopamine can well grow on the surfaces of PVDF hydrophobic membranes and PP hydrophobic membranes to form a layer of hydrophilic surface. Finally, through a method of stripping the adhesive tape, one side of the PDA/PVDF @ PP/PDA composite membrane is exposed out of the hydrophobic PDA/PVDF @ PP (figures 5 and 6), and the other side is hydrophilic PDA (figure 4), and finally the PDA/PVDF @ PP Janus membrane is obtained. The SEM result proves that the simple and efficient Janus membrane preparation method designed by the invention has practical feasibility.
Janus membrane wettability test
The Janus membrane prepared by the method has asymmetric wettability, the PDA side is a hydrophilic surface, and the water contact angle of the PDA side is about 45 degrees in combination with the figure 4; whereas the pvdf @ pp side exposed by the peeling process is a hydrophobic side, with reference to fig. 6, the water contact angle is about 133 °.
The Janus membranes obtained in example 1 were subjected to a water contact angle test, and fig. 7 to 10 were obtained.
In a complex separation environment, the Janus film prepared by the invention shows excellent asymmetric wettability. In a water environment, the PDA hydrophilic side of the Janus film can well resist oil pollution in combination with the graph of FIG. 7, and in combination with the graph of FIG. 8, the Janus film still has certain affinity to water in an oil-rich environment, so that the excellent hydrophilic and oleophobic performance of the Janus side is reflected.
Combining fig. 9 and fig. 10, on the other side of Janus, pvdf @ pp side exhibited excellent oleophilic and hydrophobic abilities (fig. 9, fig. 10).
By combining the results, the Janus film prepared by the soaking and stripping method has the capability of being practically applied to the complex feed film separation process, and the designed soaking and stripping preparation method is simple and efficient and has high industrialization possibility.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (10)
1. A Janus membrane capable of efficiently separating oil and water is characterized by comprising a porous base layer, a first hydrophobic layer arranged on the porous base layer, a second hydrophobic layer stacked on the first hydrophobic layer and a polydopamine layer stacked on the second hydrophobic layer;
the porous substrate layer is hydrophobic, and the first hydrophobic layer is partially infiltrated and fixed in the pores of the porous substrate layer.
2. The Janus film of claim 1, wherein one side of the second hydrophobic layer away from the first hydrophobic layer is provided with a concave-convex pattern for increasing surface roughness.
3. The Janus membrane of claim 1, wherein the porous substrate layer is a nonwoven fabric, the porous substrate layer has a porosity of 70% to 95%, the porous substrate layer has pores with a pore size of 15 μm to 85 μm, and the porous substrate layer has a thickness of 0.2mm to 0.8mm.
4. The Janus film of claim 1 wherein the first hydrophobic layer and the second hydrophobic layer are the same material, and the material of the first hydrophobic layer is PVDF, PSU, PES, CA, PVC, PAN, PVA, PEEK or PA;
the thickness of the first hydrophobic layer is 8-12 microns, the thickness of the second hydrophobic layer is 6.5-10 microns, and the thickness of the polydopamine layer is 1-5 microns.
5. A method of making a Janus film as defined in any one of claims 1-4, comprising the steps of:
coating a first hydrophobic organic solution on a porous substrate, immersing the porous substrate in a first coagulating bath to complete non-solvent induced phase separation and perform first curing, and drying to obtain a first semi-finished product, wherein the first semi-finished product comprises a porous substrate layer and a first hydrophobic layer arranged on the porous substrate layer, the first hydrophobic layer is partially penetrated and fixed in holes of the porous substrate layer, and the mass concentration of the first hydrophobic organic solution is 10-15%;
coating a second hydrophobic organic solution on the first hydrophobic layer of the first semi-finished product to obtain a second semi-finished product, then placing the second semi-finished product in an environment with a relative humidity of 75-85% and a room temperature for 3-10 min to complete steam-induced phase separation, then immersing the second semi-finished product into a second coagulating bath to perform second curing, so as to form a second hydrophobic layer on the first hydrophobic layer, and drying to obtain a third semi-finished product, wherein the mass concentration of the second hydrophobic organic solution is 8-12%, and the mass concentration of the second hydrophobic organic solution is less than that of the first hydrophobic organic solution;
immersing the third semi-finished product into a dopamine solution, and immersing for 8-16 h at 55-65 ℃ to form a polydopamine membrane on the outer surface of the third semi-finished product, so as to obtain a fourth semi-finished product, wherein the dopamine solution is an alkaline solution, and the mass concentration of the dopamine solution is 1-5 mg/mL; and
and removing the polydopamine film covered on the porous substrate layer in the fourth semi-finished product so as to expose the porous substrate layer, wherein the polydopamine film covered on the second hydrophobic layer is the polydopamine layer, and thus the needed Janus film is obtained.
6. The method for preparing a Janus membrane according to claim 5, wherein the step of coating a second hydrophobic organic solution on the first hydrophobic layer of the first semi-finished product to obtain a second semi-finished product, the second semi-finished product is then placed in an environment with a relative humidity of 75-85% and a room temperature for 3-10 min to complete steam-induced phase separation, the second semi-finished product is then immersed in a second coagulation bath for a second time of curing, so that a second hydrophobic layer is formed on the first hydrophobic layer, and the step of drying to obtain a third semi-finished product is as follows:
coating a second hydrophobic organic solution on the first hydrophobic layer of the first semi-finished product, fixing a gasket with concave-convex patterns on the surface on the second hydrophobic organic solution to obtain a second semi-finished product, then placing the second semi-finished product in an environment with the relative humidity of 75-85% and the room temperature for 3-10 min to complete steam-induced phase separation, then immersing the second semi-finished product in a second coagulating bath, removing the gasket after 40-90 s, continuing to perform second curing to form a second hydrophobic layer on the first hydrophobic layer, forming concave-convex patterns corresponding to the gasket with concave-convex patterns on one surface of the second hydrophobic layer far away from the first hydrophobic layer, and drying to obtain a third semi-finished product.
7. The method of making a Janus membrane as in claim 6, wherein the textured gasket is a diamond-shaped corrugated gasket.
8. The method of claim 6, wherein the solvent of the first hydrophobic organic solution is N, N-dimethylacetamide;
the time of the first curing is 30-50 min, and the first coagulation bath is a deionized water coagulation bath.
9. The method of claim 6, wherein the solvent of the second hydrophobic organic solution is N, N-dimethylacetamide;
the time of the second curing is 40-50 min, and the second coagulation bath is a deionized water coagulation bath.
10. The method for preparing a Janus membrane according to claim 5, wherein the step of removing the polydopamine membrane coated on the porous substrate layer in the fourth semi-finished product comprises:
peeling the polydopamine film covered on the porous substrate layer in the fourth semi-finished product with an adhesive tape.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210698771.7A CN115228305A (en) | 2022-06-20 | 2022-06-20 | Janus film and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210698771.7A CN115228305A (en) | 2022-06-20 | 2022-06-20 | Janus film and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115228305A true CN115228305A (en) | 2022-10-25 |
Family
ID=83668811
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210698771.7A Pending CN115228305A (en) | 2022-06-20 | 2022-06-20 | Janus film and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115228305A (en) |
Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104307387A (en) * | 2014-10-11 | 2015-01-28 | 南京九思高科技有限公司 | Polyvinylidene fluoride-hexafluoropropylene super-hydrophobic composite film and preparation method thereof |
| CN108404685A (en) * | 2018-04-14 | 2018-08-17 | 哈尔滨工业大学 | A kind of high penetration, resistance to wetting, pollution-resistant membrane distillation distillation film preparation method |
| US20180345227A1 (en) * | 2017-06-01 | 2018-12-06 | Vanderbilt University | Composite membranes and methods of making and use thereof |
| CN109276998A (en) * | 2018-08-28 | 2019-01-29 | 中国科学院宁波材料技术与工程研究所 | A kind of high-performance Janus forward osmosis membrane and preparation method thereof |
| US20190262777A1 (en) * | 2018-02-26 | 2019-08-29 | Gvs S.P.A. | Macroporous polyvinylidene fluoride (pvdf) membranes |
| CN110404421A (en) * | 2019-09-02 | 2019-11-05 | 哈尔滨工业大学（威海） | A kind of preparation method of Janus Kynoar (PVDF) seperation film |
| CN111632581A (en) * | 2019-03-01 | 2020-09-08 | 江南大学 | Raspberry-like super-hydrophobic oleophylic cotton fiber oil-water adsorption/separation membrane and preparation method and application thereof |
| CN111744369A (en) * | 2020-05-20 | 2020-10-09 | 山东大学 | Janus type distillation membrane with wetting resistance and oil stain resistance as well as preparation method and application thereof |
| CN212356645U (en) * | 2020-03-23 | 2021-01-15 | 中新瑞美(天津)环保科技有限公司 | Separation membrane for groundwater pollution remediation |
| CN112755805A (en) * | 2020-12-09 | 2021-05-07 | 山东大学 | Underwater super-oleophobic two-dimensional nanoscale mica sheet oil-water separation membrane and preparation method and application thereof |
| CN112808022A (en) * | 2020-12-31 | 2021-05-18 | 太原科技大学 | Polyvinyl amine membrane with hydrophilic and hydrophobic functional groups and preparation method and application thereof |
| WO2022049900A1 (en) * | 2020-09-02 | 2022-03-10 | 東洋紡株式会社 | Laminated film |
| CN114432914A (en) * | 2022-04-08 | 2022-05-06 | 生态环境部华南环境科学研究所 | Nanofiber Janus membrane for saline membrane distillation treatment and preparation method thereof |
-
2022
- 2022-06-20 CN CN202210698771.7A patent/CN115228305A/en active Pending
Patent Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104307387A (en) * | 2014-10-11 | 2015-01-28 | 南京九思高科技有限公司 | Polyvinylidene fluoride-hexafluoropropylene super-hydrophobic composite film and preparation method thereof |
| US20180345227A1 (en) * | 2017-06-01 | 2018-12-06 | Vanderbilt University | Composite membranes and methods of making and use thereof |
| US20190262777A1 (en) * | 2018-02-26 | 2019-08-29 | Gvs S.P.A. | Macroporous polyvinylidene fluoride (pvdf) membranes |
| CN108404685A (en) * | 2018-04-14 | 2018-08-17 | 哈尔滨工业大学 | A kind of high penetration, resistance to wetting, pollution-resistant membrane distillation distillation film preparation method |
| CN109276998A (en) * | 2018-08-28 | 2019-01-29 | 中国科学院宁波材料技术与工程研究所 | A kind of high-performance Janus forward osmosis membrane and preparation method thereof |
| CN111632581A (en) * | 2019-03-01 | 2020-09-08 | 江南大学 | Raspberry-like super-hydrophobic oleophylic cotton fiber oil-water adsorption/separation membrane and preparation method and application thereof |
| CN110404421A (en) * | 2019-09-02 | 2019-11-05 | 哈尔滨工业大学（威海） | A kind of preparation method of Janus Kynoar (PVDF) seperation film |
| CN212356645U (en) * | 2020-03-23 | 2021-01-15 | 中新瑞美(天津)环保科技有限公司 | Separation membrane for groundwater pollution remediation |
| CN111744369A (en) * | 2020-05-20 | 2020-10-09 | 山东大学 | Janus type distillation membrane with wetting resistance and oil stain resistance as well as preparation method and application thereof |
| WO2022049900A1 (en) * | 2020-09-02 | 2022-03-10 | 東洋紡株式会社 | Laminated film |
| CN112755805A (en) * | 2020-12-09 | 2021-05-07 | 山东大学 | Underwater super-oleophobic two-dimensional nanoscale mica sheet oil-water separation membrane and preparation method and application thereof |
| CN112808022A (en) * | 2020-12-31 | 2021-05-18 | 太原科技大学 | Polyvinyl amine membrane with hydrophilic and hydrophobic functional groups and preparation method and application thereof |
| CN114432914A (en) * | 2022-04-08 | 2022-05-06 | 生态环境部华南环境科学研究所 | Nanofiber Janus membrane for saline membrane distillation treatment and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| An et al. | Amphiphobic surface modification of electrospun nanofibrous membranes for anti-wetting performance in membrane distillation | |
| Song et al. | Asymmetric Janus membranes based on in situ mussel-inspired chemistry for efficient oil/water separation | |
| CN105709619B (en) | A kind of positively charged nanofiltration membranes and preparation method thereof | |
| CN102068924B (en) | Polytetrafluoroethylene composite membrane and preparation method thereof | |
| US5376273A (en) | Supported microporous membrane | |
| CA2432046A1 (en) | Separation membrane, separation membrane element, separation membrane module, sewage treatment apparatus, and method for making the separation membrane | |
| Yang et al. | Polymer membrane with a mineral coating for enhanced curling resistance and surface wettability | |
| CN103182253B (en) | Desalination filter material | |
| Hu et al. | Designing high-caliber nonwoven filter mats for coalescence filtration of oil/water emulsions | |
| CN109126463A (en) | A kind of preparation method of the high-flux nanofiltration membrane of middle layer containing micropore | |
| EP4052782A1 (en) | Polymer-based film, preparation method therefor, and use thereof | |
| CN104998552B (en) | A kind of oil-water separation mesh film and preparation method and application | |
| CN108043241B (en) | A kind of composite separating film and preparation method thereof with non-directional nanochannel | |
| JPWO2013125505A1 (en) | Separation membrane and separation membrane element | |
| JP6237232B2 (en) | Composite semipermeable membrane | |
| CN108421418A (en) | Super hydrophobic porous film and its preparation method and application | |
| CN112642300A (en) | Oil-water separation membrane and preparation method and application thereof | |
| CN110545903A (en) | Membrane permeability-enhanced thin film composite membranes with nano-sized bubbles, methods of making and uses thereof | |
| Yang et al. | Janus polyvinylidene fluoride membranes with controllable asymmetric configurations and opposing surface wettability fabricated via nanocasting for emulsion separation | |
| CN106687201A (en) | Spiral membrane element | |
| Xi et al. | High flux composite membranes based on glass/cellulose fibers for efficient oil-water emulsion separation | |
| KR20180062550A (en) | manufacturing method of forward osmosis filter using carbon nano-material | |
| Chen et al. | Superhydrophilic/underwater superoleophobic PVDF ultrafiltration membrane with pH-responsive self-cleaning performance for efficient oil-water separation | |
| CN115228305A (en) | Janus film and preparation method thereof | |
| CN110394069A (en) | Using the polyamide composite film of inorganic additives preparation, its preparation and application |
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 |