CN117654287A - Composite membrane and preparation method and application thereof - Google Patents
Composite membrane and preparation method and application thereof Download PDFInfo
- Publication number
- CN117654287A CN117654287A CN202410141028.0A CN202410141028A CN117654287A CN 117654287 A CN117654287 A CN 117654287A CN 202410141028 A CN202410141028 A CN 202410141028A CN 117654287 A CN117654287 A CN 117654287A
- Authority
- CN
- China
- Prior art keywords
- layer
- heat treatment
- hydrogel
- membrane
- solution
- 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
- 239000012528 membrane Substances 0.000 title claims abstract description 133
- 239000002131 composite material Substances 0.000 title claims abstract description 89
- 238000002360 preparation method Methods 0.000 title abstract description 21
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonia chloride Chemical compound [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 claims abstract description 93
- 239000000243 solution Substances 0.000 claims abstract description 90
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 84
- 239000000017 hydrogel Substances 0.000 claims abstract description 73
- 239000004372 Polyvinyl alcohol Substances 0.000 claims abstract description 59
- 229920002451 polyvinyl alcohol Polymers 0.000 claims abstract description 59
- 238000010438 heat treatment Methods 0.000 claims abstract description 50
- 239000007864 aqueous solution Substances 0.000 claims abstract description 47
- 235000019270 ammonium chloride Nutrition 0.000 claims abstract description 45
- 239000011259 mixed solution Substances 0.000 claims abstract description 36
- 238000002425 crystallisation Methods 0.000 claims abstract description 24
- 230000008025 crystallization Effects 0.000 claims abstract description 24
- 229920006318 anionic polymer Polymers 0.000 claims abstract description 21
- 238000002156 mixing Methods 0.000 claims abstract description 20
- 239000003431 cross linking reagent Substances 0.000 claims abstract description 16
- 238000000926 separation method Methods 0.000 claims abstract description 16
- 239000003377 acid catalyst Substances 0.000 claims abstract description 14
- 150000001263 acyl chlorides Chemical class 0.000 claims abstract description 8
- 150000001412 amines Chemical class 0.000 claims abstract description 5
- 239000012071 phase Substances 0.000 claims description 63
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 26
- GLUUGHFHXGJENI-UHFFFAOYSA-N Piperazine Chemical compound C1CNCCN1 GLUUGHFHXGJENI-UHFFFAOYSA-N 0.000 claims description 24
- 239000008346 aqueous phase Substances 0.000 claims description 21
- 229920001495 poly(sodium acrylate) polymer Polymers 0.000 claims description 20
- NNMHYFLPFNGQFZ-UHFFFAOYSA-M sodium polyacrylate Chemical compound [Na+].[O-]C(=O)C=C NNMHYFLPFNGQFZ-UHFFFAOYSA-M 0.000 claims description 20
- 238000000034 method Methods 0.000 claims description 17
- SXRSQZLOMIGNAQ-UHFFFAOYSA-N Glutaraldehyde Chemical compound O=CCCCC=O SXRSQZLOMIGNAQ-UHFFFAOYSA-N 0.000 claims description 15
- UWCPYKQBIPYOLX-UHFFFAOYSA-N benzene-1,3,5-tricarbonyl chloride Chemical compound ClC(=O)C1=CC(C(Cl)=O)=CC(C(Cl)=O)=C1 UWCPYKQBIPYOLX-UHFFFAOYSA-N 0.000 claims description 12
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 10
- LEQAOMBKQFMDFZ-UHFFFAOYSA-N glyoxal Chemical compound O=CC=O LEQAOMBKQFMDFZ-UHFFFAOYSA-N 0.000 claims description 10
- 238000004519 manufacturing process Methods 0.000 claims description 8
- 229920000768 polyamine Polymers 0.000 claims description 7
- ZNZYKNKBJPZETN-WELNAUFTSA-N Dialdehyde 11678 Chemical group N1C2=CC=CC=C2C2=C1[C@H](C[C@H](/C(=C/O)C(=O)OC)[C@@H](C=C)C=O)NCC2 ZNZYKNKBJPZETN-WELNAUFTSA-N 0.000 claims description 6
- 150000007522 mineralic acids Chemical group 0.000 claims description 6
- VLTRZXGMWDSKGL-UHFFFAOYSA-N perchloric acid Chemical compound OCl(=O)(=O)=O VLTRZXGMWDSKGL-UHFFFAOYSA-N 0.000 claims description 6
- 229940015043 glyoxal Drugs 0.000 claims description 5
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 claims description 4
- 229920001467 poly(styrenesulfonates) Polymers 0.000 claims description 4
- 229940006186 sodium polystyrene sulfonate Drugs 0.000 claims description 4
- WZCQRUWWHSTZEM-UHFFFAOYSA-N 1,3-phenylenediamine Chemical compound NC1=CC=CC(N)=C1 WZCQRUWWHSTZEM-UHFFFAOYSA-N 0.000 claims description 3
- CBCKQZAAMUWICA-UHFFFAOYSA-N 1,4-phenylenediamine Chemical compound NC1=CC=C(N)C=C1 CBCKQZAAMUWICA-UHFFFAOYSA-N 0.000 claims description 3
- BMYNFMYTOJXKLE-UHFFFAOYSA-N 3-azaniumyl-2-hydroxypropanoate Chemical compound NCC(O)C(O)=O BMYNFMYTOJXKLE-UHFFFAOYSA-N 0.000 claims description 3
- WSMYVTOQOOLQHP-UHFFFAOYSA-N Malondialdehyde Chemical compound O=CCC=O WSMYVTOQOOLQHP-UHFFFAOYSA-N 0.000 claims description 3
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims description 3
- 229920002873 Polyethylenimine Polymers 0.000 claims description 3
- PCSMJKASWLYICJ-UHFFFAOYSA-N Succinic aldehyde Chemical compound O=CCCC=O PCSMJKASWLYICJ-UHFFFAOYSA-N 0.000 claims description 3
- 239000002253 acid Substances 0.000 claims description 3
- 125000000129 anionic group Chemical group 0.000 claims description 3
- FDQSRULYDNDXQB-UHFFFAOYSA-N benzene-1,3-dicarbonyl chloride Chemical compound ClC(=O)C1=CC=CC(C(Cl)=O)=C1 FDQSRULYDNDXQB-UHFFFAOYSA-N 0.000 claims description 3
- 229960000587 glutaral Drugs 0.000 claims description 3
- XMBWDFGMSWQBCA-UHFFFAOYSA-N hydrogen iodide Chemical compound I XMBWDFGMSWQBCA-UHFFFAOYSA-N 0.000 claims description 3
- 229940071870 hydroiodic acid Drugs 0.000 claims description 3
- 229940018564 m-phenylenediamine Drugs 0.000 claims description 3
- 229940118019 malondialdehyde Drugs 0.000 claims description 3
- 229910017604 nitric acid Inorganic materials 0.000 claims description 3
- 229920002401 polyacrylamide Polymers 0.000 claims description 3
- LXEJRKJRKIFVNY-UHFFFAOYSA-N terephthaloyl chloride Chemical compound ClC(=O)C1=CC=C(C(Cl)=O)C=C1 LXEJRKJRKIFVNY-UHFFFAOYSA-N 0.000 claims description 3
- FAGUFWYHJQFNRV-UHFFFAOYSA-N tetraethylenepentamine Chemical compound NCCNCCNCCNCCN FAGUFWYHJQFNRV-UHFFFAOYSA-N 0.000 claims description 3
- 230000004907 flux Effects 0.000 abstract description 29
- 230000014759 maintenance of location Effects 0.000 abstract description 4
- 239000010410 layer Substances 0.000 description 181
- 229920002492 poly(sulfone) Polymers 0.000 description 32
- 238000004132 cross linking Methods 0.000 description 23
- 239000011248 coating agent Substances 0.000 description 16
- 238000000576 coating method Methods 0.000 description 16
- 230000000052 comparative effect Effects 0.000 description 14
- 238000001035 drying Methods 0.000 description 10
- 239000011148 porous material Substances 0.000 description 10
- 238000012695 Interfacial polymerization Methods 0.000 description 9
- 238000006243 chemical reaction Methods 0.000 description 9
- 230000009471 action Effects 0.000 description 8
- 239000013078 crystal Substances 0.000 description 8
- 239000012141 concentrate Substances 0.000 description 6
- 238000010612 desalination reaction Methods 0.000 description 5
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 5
- CSNNHWWHGAXBCP-UHFFFAOYSA-L Magnesium sulfate Chemical compound [Mg+2].[O-][S+2]([O-])([O-])[O-] CSNNHWWHGAXBCP-UHFFFAOYSA-L 0.000 description 4
- 125000003158 alcohol group Chemical group 0.000 description 4
- 150000002500 ions Chemical class 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- 239000002904 solvent Substances 0.000 description 4
- 239000004952 Polyamide Substances 0.000 description 3
- 229910052739 hydrogen Inorganic materials 0.000 description 3
- 239000001257 hydrogen Substances 0.000 description 3
- 239000002105 nanoparticle Substances 0.000 description 3
- 229920002647 polyamide Polymers 0.000 description 3
- 239000002244 precipitate Substances 0.000 description 3
- 239000013535 sea water Substances 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 230000002378 acidificating effect Effects 0.000 description 2
- -1 and meanwhile Substances 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 239000003651 drinking water Substances 0.000 description 2
- 235000020188 drinking water Nutrition 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 229910052943 magnesium sulfate Inorganic materials 0.000 description 2
- 235000019341 magnesium sulphate Nutrition 0.000 description 2
- 239000012466 permeate Substances 0.000 description 2
- 239000011241 protective layer Substances 0.000 description 2
- 239000012266 salt solution Substances 0.000 description 2
- CNPVJWYWYZMPDS-UHFFFAOYSA-N 2-methyldecane Chemical compound CCCCCCCCC(C)C CNPVJWYWYZMPDS-UHFFFAOYSA-N 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- JLVVSXFLKOJNIY-UHFFFAOYSA-N Magnesium ion Chemical compound [Mg+2] JLVVSXFLKOJNIY-UHFFFAOYSA-N 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 238000004220 aggregation Methods 0.000 description 1
- 238000005882 aldol condensation reaction Methods 0.000 description 1
- 238000006065 biodegradation reaction Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000000499 gel Substances 0.000 description 1
- 229910001425 magnesium ion Inorganic materials 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 238000001728 nano-filtration Methods 0.000 description 1
- 231100000252 nontoxic Toxicity 0.000 description 1
- 230000003000 nontoxic effect Effects 0.000 description 1
- 239000004014 plasticizer Substances 0.000 description 1
- 229920002239 polyacrylonitrile Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- BDHFUVZGWQCTTF-UHFFFAOYSA-M sulfonate Chemical compound [O-]S(=O)=O BDHFUVZGWQCTTF-UHFFFAOYSA-M 0.000 description 1
- 229920002554 vinyl polymer Polymers 0.000 description 1
Abstract
The invention relates to a composite membrane, a preparation method and application thereof, wherein the preparation method of the composite membrane comprises the following steps: mixing a polyvinyl alcohol aqueous solution and an anionic polymer to obtain hydrogel, and then placing the hydrogel on any surface of a porous support membrane to form a hydrogel layer; preparing a mixed solution from a cross-linking agent and an acid catalyst, placing the mixed solution on the surface of the hydrogel layer far away from the porous support membrane, and forming a prefabricated intermediate layer through first heat treatment; placing the porous support film with the prefabricated intermediate layer in an ammonium chloride aqueous solution, taking out and performing second heat treatment to form an intermediate layer, wherein a crystallization layer is distributed on the surface of the intermediate layer; and sequentially placing an oil phase solution and a water phase solution on the surface of the middle layer far away from the porous support membrane, and forming a separation layer through third heat treatment to obtain the composite membrane, wherein the oil phase solution comprises polybasic acyl chloride, and the water phase solution comprises polybasic amine. The composite membrane prepared by the preparation method can maintain high retention rate while having high water flux when being applied to water treatment.
Description
Technical Field
The invention relates to the technical field of water treatment, in particular to a composite membrane and a preparation method and application thereof.
Background
The flux and the desalination rate of the composite membrane have a relationship with each other, and the improvement of the water flux and the desalination rate of the composite membrane becomes a technical bottleneck of the membrane industry, so that the high retention rate is difficult to achieve while the high water flux is maintained. There are many methods for preparing the composite film, and the interfacial polymerization method is one of the methods commonly used in the preparation of composite films.
Currently, in the process of preparing a composite membrane by adopting an interfacial polymerization method, in order to improve the water flux of the composite membrane, the following three modes are generally adopted: in the first mode, nanoparticles are added in a water phase or an oil phase, but the problem of nanoparticle aggregation easily occurs in the mode, and meanwhile, the nanoparticles are easy to fall off or escape due to the lack of effective adhesion force with a separation layer, so that the problem of drinking water safety exists when the method is applied to drinking water treatment; in the second way, hydrophilic substances are added to the aqueous phase, but in this way, the improvement of membrane flux is not obvious because hydrophilic substances are difficult to diffuse into the oil phase; in the third method, an ester plasticizer is added to the oil phase, and this method can increase the water flux, but generally results in a loss of the desalination rate of the composite membrane.
Therefore, the composite membrane prepared by the traditional interfacial polymerization method is difficult to have high water flux and high rejection rate.
Disclosure of Invention
Based on this, it is necessary to provide a composite membrane, a preparation method thereof, and an application thereof, which can maintain a high rejection rate while having a high water flux when applied to water treatment.
A method of preparing a composite membrane comprising:
mixing a polyvinyl alcohol aqueous solution and an anionic polymer to obtain hydrogel, and then placing the hydrogel on any surface of a porous support membrane to form a hydrogel layer;
preparing a mixed solution from a cross-linking agent and an acid catalyst, placing the mixed solution on the surface of the hydrogel layer far away from the porous support membrane, and forming a prefabricated intermediate layer through first heat treatment;
placing the porous support film with the prefabricated middle layer in an ammonium chloride aqueous solution, taking out and performing second heat treatment to form a middle layer, wherein a crystallization layer is distributed on the surface of the middle layer;
and sequentially placing an oil phase solution and a water phase solution on the surface of the middle layer far away from the porous support membrane, and forming a separation layer through third heat treatment to obtain the composite membrane, wherein the oil phase solution comprises polybasic acyl chloride, and the water phase solution comprises polybasic amine.
In one embodiment, the mass fraction of polyvinyl alcohol in the aqueous solution of polyvinyl alcohol is 0.1% -0.5%;
in one embodiment, the mass fraction of the anionic polymer in the hydrogel is 0.1% to 0.3%;
and/or the anionic polymer is at least one selected from sodium polyacrylate, anionic polyacrylamide or sodium polystyrene sulfonate.
In one embodiment, the mass fraction of ammonium chloride in the aqueous solution of ammonium chloride is 3% -8%.
In one embodiment, the mass fraction of the cross-linking agent in the mixed solution is 0.1% -1%;
and/or the cross-linking agent is dialdehyde, and the dialdehyde is at least one selected from glutaraldehyde, glyoxal, malondialdehyde and succinaldehyde;
and/or the mass fraction of the acid catalyst in the mixed solution is 0.01% -0.05%;
and/or the acid catalyst is selected from inorganic acid, and the inorganic acid is at least one of hydrochloric acid, sulfuric acid, nitric acid, perchloric acid, hydrobromic acid, permanganic acid and hydroiodic acid.
In one embodiment, the mass fraction of the polyamine in the aqueous solution is 0.1% to 0.5%;
and/or the polyamine is at least one selected from piperazine, polyethyleneimine, m-phenylenediamine, p-phenylenediamine and tetraethylenepentamine.
In one embodiment, the mass fraction of the polyacyl chloride in the oil phase solution is 0.1% -0.3%;
and/or the polybasic acyl chloride is selected from at least one of trimesoyl chloride, isophthaloyl chloride and terephthaloyl chloride.
In one embodiment, the first heat treatment temperature is 60-90 ℃, and the first heat treatment time is 3-5 min;
and/or the second heat treatment temperature is 70-110 ℃, and the second heat treatment temperature is 2-3 min;
and/or the third heat treatment temperature is 70-95 ℃, and the third heat treatment temperature is 2-3 min.
The composite membrane is prepared by the preparation method of the composite membrane.
Use of a composite membrane as described above in a water treatment device.
In the preparation method of the composite membrane, a hydrogel layer is formed on the surface of a porous support membrane, then a polyvinyl alcohol has abundant hydroxyl groups and other groups to form reactive sites, and under the action of an acid catalyst, a polyvinyl alcohol chain segment in the hydrogel layer and a cross-linking agent undergo a cross-linking reaction to form a polyvinyl alcohol cross-linking layer interpenetrating with the hydrogel layer, so that a prefabricated intermediate layer is formed; meanwhile, the anionic polymer in the hydrogel layer can reduce the crosslinking density of the polyvinyl alcohol, so that the formed polyvinyl alcohol crosslinking layer has discontinuity, and the problem that the water flux is influenced due to the fact that the polyvinyl alcohol crosslinking layer is too compact is avoided.
In the process of placing the prefabricated middle layer in the ammonium chloride aqueous solution, the anionic polymer can be dissolved and separated from the hydrogel layer, so that a space is reserved, the entry of the ammonium chloride aqueous solution is facilitated, and meanwhile, a water production channel can be correspondingly increased, and the problem of water flux caused by too dense polyvinyl alcohol crosslinking layer is further avoided; meanwhile, the ammonium chloride aqueous solution is dispersed in the prefabricated middle layer, the supersaturated ammonium chloride aqueous solution is formed and separated out after the second heat treatment, the middle layer with the surface provided with the crystallization layer is formed, and the middle layer has a large specific surface area due to the existence of the crystallization layer, so that the water-oil interface has a large specific surface area, and the separation layer formed by the interfacial polymerization reaction also has a large specific surface area, so that the water flux of the composite membrane is improved.
In addition, the invention adopts a mode of water phase and oil phase exchange sequence to be arranged in the middle layer, can effectively ensure the appearance of the crystallization layer on the surface of the middle layer, ensures that interfacial polymerization occurs on the surface of crystals and forms a separation layer with high specific surface area, and avoids the problem that the crystal on the surface of the middle layer is dissolved by water to damage the crystallization structure.
Therefore, the composite membrane provided by the invention has high water flux and high rejection rate when being applied to water treatment.
Drawings
FIG. 1 is an electron microscopic view of a composite film prepared in example 1 of the present invention;
FIG. 2 is an electron microscopic view of the composite film prepared in comparative example 1 of the present invention;
FIG. 3 is an electron microscopic view of the composite film prepared in comparative example 2 of the present invention;
FIG. 4 is an electron microscopic image of the composite film prepared in comparative example 3 of the present invention.
Detailed Description
The composite film provided by the invention, and the preparation method and application thereof will be further described below.
The preparation method of the composite film provided by the invention comprises the following steps:
mixing a polyvinyl alcohol aqueous solution and an anionic polymer to obtain hydrogel, and then placing the hydrogel on any surface of a porous support membrane to form a hydrogel layer;
preparing a mixed solution from a cross-linking agent and an acid catalyst, placing the mixed solution on the surface of the hydrogel layer far away from the porous support membrane, and forming a prefabricated intermediate layer through first heat treatment;
placing the porous support film with the prefabricated middle layer in an ammonium chloride aqueous solution, taking out and performing second heat treatment to form a middle layer, wherein a crystallization layer is distributed on the surface of the middle layer;
and sequentially placing an oil phase solution and a water phase solution on the surface of the middle layer far away from the porous support membrane, and forming a separation layer through third heat treatment to obtain the composite membrane, wherein the oil phase solution comprises polybasic acyl chloride, and the water phase solution comprises polybasic amine.
Specifically, an aqueous solution of polyvinyl alcohol and an anionic polymer are mixed, a hydrogel with an interpenetrating network is formed between the two through intermolecular hydrogen bonding, when the hydrogel is placed on the surface of a porous support membrane, the hydrogel can enter membrane pores of the porous support membrane, the hydrogel can fill the membrane pores and extend to the surface of the porous support membrane to form a hydrogel layer, and the hydrogel layer covers the surface of the porous support membrane.
When the mixed solution is placed on the surface of the hydrogel layer, the cross-linking agent and the acid catalyst are dispersed in the hydrogel, and the polyvinyl alcohol has abundant hydroxyl groups and other groups so as to have reactive sites, and under the action of the acid catalyst and the first heat treatment, the polyvinyl alcohol chain segment in the hydrogel layer and the cross-linking agent undergo a cross-linking reaction to form a polyvinyl alcohol cross-linking layer interpenetrating the hydrogel layer, and at the moment, the hydrogel layer and the polyvinyl alcohol cross-linking layer jointly form the prefabricated intermediate layer.
Meanwhile, the anionic polymer in the hydrogel layer can not generate a crosslinking reaction with the crosslinking agent, so that the formed polyvinyl alcohol crosslinking layer has discontinuity due to the existence of the anionic polymer, and the problem that the water flux is influenced due to the fact that the polyvinyl alcohol crosslinking layer is too compact is avoided.
When the porous support film with the prefabricated middle layer is placed in an ammonium chloride aqueous solution, the ammonium chloride aqueous solution can be dispersed in the prefabricated middle layer, meanwhile, the anionic polymer is easy to dissolve in water, so that the anionic polymer can be dissolved and separated from the hydrogel layer, and at the moment, the prefabricated middle layer is only composed of a polyvinyl alcohol crosslinked layer; on the one hand, the anionic polymer is separated, so that a space is reserved for the entry of an ammonium chloride aqueous solution, on the other hand, a water production channel can be correspondingly increased, and the problem of water flux caused by too dense polyvinyl alcohol crosslinking layers is further avoided.
It can be understood that the polyvinyl alcohol chain segment has rich hydrophilic groups such as hydroxyl groups, so that the prefabricated intermediate layer has good hydrophilicity, and the water flux of the composite membrane is further improved.
Taking the porous support film with the prefabricated middle layer out of the ammonium chloride aqueous solution, and then performing second heat treatment, wherein the ammonium chloride aqueous solution dispersed in the prefabricated middle layer can form supersaturated ammonium chloride aqueous solution and precipitate out under the action of the second heat treatment to form the middle layer with a crystallization layer distributed on the surface, and the middle layer has a large specific surface area due to the crystallization layer distributed on the surface.
Therefore, when the oil phase solution and the water phase solution are sequentially arranged on the surface of the intermediate layer, the water phase solution and the oil phase solution can contact on the surface of the intermediate layer to form a water-oil interface, and the crystallization layer is distributed on the surface of the intermediate layer, so that the water-oil interface is formed on the crystallization layer, the water-oil interface has a large specific surface area, and the separation layer formed by the interfacial polymerization reaction of the polyamine and the polyacyl chloride at the water-oil interface also has a large specific surface area, so that the water flux of the composite membrane is improved.
It will be appreciated that the dispersion of the aqueous ammonium chloride solution in the pre-fabricated intermediate layer means that the aqueous ammonium chloride solution is dispersed both inside the pre-fabricated intermediate layer and on the surface of the pre-fabricated intermediate layer, and therefore, under the effect of the second heat treatment, the aqueous ammonium chloride solution precipitates to form a crystalline layer, which is not only present on the surface of the pre-fabricated intermediate layer but also distributed inside the pre-fabricated intermediate layer.
In addition, in order to prevent the aqueous phase solution from damaging the morphology of the crystallization layer on the surface of the intermediate layer and affecting the specific surface area of the intermediate layer, the invention firstly places the oil phase solution on the surface of the intermediate layer to form a protective layer, and then places the aqueous phase solution on the surface of the intermediate layer. On one hand, the formation of the protective layer can effectively prevent the aqueous phase solution from directly contacting with the crystallization layer, and avoid the problem that crystals on the surface of the middle layer are dissolved by water to damage the crystallization structure, thereby ensuring that the separation layer has a large specific surface area and further improving the water flux of the composite membrane; on the other hand, the method is convenient for the interfacial polymerization reaction of the polybasic acyl chloride and the polybasic amine on the surface of the intermediate layer to form a separating layer, and ensures the high retention rate of the composite membrane.
Therefore, the invention adopts a mode of water phase and oil phase exchange sequence to be arranged in the middle layer, namely, reverse phase interfacial polymerization is utilized, the morphology of the crystallization layer on the surface of the middle layer can be effectively ensured, the interfacial polymerization occurs on the surface of the crystal and forms a separation layer with high specific surface area, and the problem that the crystal on the surface of the middle layer is dissolved by water to damage the crystallization structure is avoided.
Therefore, the composite membrane provided by the invention has high water flux and high rejection rate when being applied to water treatment.
It should be noted that, the composite membrane just prepared is usually soaked into water for standby, and the ammonium chloride crystals are dissolved in water and are separated from the middle layer of the composite membrane, so that the water yield channel is correspondingly increased, and the water flux of the composite membrane is further improved.
Optionally, the mass fraction of the polyvinyl alcohol in the polyvinyl alcohol aqueous solution is 0.1% -0.5%; the hydrogel with a network structure can be formed by combining hydrogen bonds with the anionic polymer, and on the other hand, the hydrogel can provide abundant hydroxyl groups and other groups to have reactive sites, so that the hydrogel can be subjected to crosslinking reaction with a crosslinking agent to form a polyvinyl alcohol crosslinked layer under the action of an acid catalyst. Meanwhile, rich hydrophilic groups are provided, so that the hydrophilicity of the composite membrane is further improved, and the water flux of the composite membrane is further improved.
Optionally, the mass fraction of the anionic polymer in the hydrogel is 0.1% -0.3%, and the anionic polymer is at least one selected from sodium polyacrylate, anionic polyacrylamide or sodium polystyrene sulfonate, preferably sodium polyacrylate. By means of the arrangement, on one hand, complete gel with a network structure can be formed by hydrogen bonds with the polyvinyl alcohol, meanwhile, the crosslinking density of subsequent polyvinyl alcohol crosslinking reaction can be controlled better, a discontinuous polyvinyl alcohol crosslinking layer is formed, and the problem of water flux caused by too dense polyvinyl alcohol crosslinking layer is avoided.
Optionally, the mass fraction of the cross-linking agent in the mixed solution is 0.1% -1%, so that the cross-linking layer of the polyvinyl alcohol interpenetrating with the hydrogel layer can be better formed.
Further, the cross-linking agent is dialdehyde, and the dialdehyde is at least one selected from glutaraldehyde, glyoxal, malondialdehyde and succinaldehyde, preferably glutaraldehyde.
Optionally, the mass fraction of the acidic catalyst in the mixed solution is 0.01% -0.05%, the acidic catalyst is selected from inorganic acid, and the inorganic acid is at least one of hydrochloric acid, sulfuric acid, nitric acid, perchloric acid, hydrobromic acid, permanganic acid and hydroiodic acid, preferably sulfuric acid. The preparation method can better utilize the characteristic that the polyvinyl alcohol has abundant hydroxyl groups and has better reactivity, can carry out aldol condensation reaction with glutaraldehyde under the action of an acid catalyst, and forms a three-dimensional interpenetrating network structure with good hydrophilicity on the surface and inside of the hydrogel layer, namely a polyvinyl alcohol crosslinked layer.
In one embodiment, the solvent in the mixed solution is water.
Optionally, the first heat treatment temperature is 60-90 ℃, and the first heat treatment time is 3-5 min. By the arrangement, the polyvinyl alcohol chain segment in the hydrogel layer can be subjected to more sufficient crosslinking reaction with the crosslinking agent under the action of the acid catalyst to form a complete polyvinyl alcohol crosslinked layer.
Optionally, the mass fraction of ammonium chloride in the ammonium chloride aqueous solution is 3% -8%. On one hand, the preparation method is favorable for fully dissolving the anionic polymer and completely removing the anionic polymer from the hydrogel layer, so that the prefabricated middle layer is only formed by a discontinuous polyvinyl alcohol crosslinked layer, and meanwhile, ammonium chloride is convenient to disperse in the polyvinyl alcohol crosslinked layer; on the other hand, ammonium chloride crystals are separated out from the inner part and the surface of the polyvinyl alcohol crosslinking layer under the action of the second heat treatment, and a crystallization layer is formed, so that the formed intermediate layer has a large specific surface area.
Optionally, the second heat treatment temperature is 70-110 ℃, and the second heat treatment temperature is 2-3 min. By the arrangement, the ammonium chloride aqueous solution dispersed in the polyvinyl alcohol crosslinking layer can be heated to better form supersaturated ammonium chloride solution and precipitate to form a crystallization layer.
Optionally, the mass fraction of the polyamine in the aqueous phase solution is 0.1% -0.5%, and the mass fraction of the polyacyl chloride in the oil phase solution is 0.1% -0.3%; by the arrangement, the polyamide layer can be crosslinked more completely, and the high rejection rate of the composite membrane can be better ensured.
Further, the polyamine is at least one selected from piperazine, polyethyleneimine, m-phenylenediamine, p-phenylenediamine and tetraethylenepentamine, preferably piperazine; the polybasic acyl chloride is at least one selected from trimesoyl chloride, isophthaloyl chloride and terephthaloyl chloride, and preferably trimesoyl chloride.
Optionally, the third heat treatment temperature is 70-95 ℃, and the third heat treatment temperature is 2-3 min. By the arrangement, the integrality and uniformity of the cross-linking of the polyamide layer can be further ensured, the polyamide layer with uniform pore diameter is formed, and the high rejection rate of the composite membrane can be better ensured.
In one embodiment, the porous support membrane comprises at least one of a polysulfone membrane, a polypropylene membrane or a polyacrylonitrile membrane, wherein polysulfone is cheap and easily available, and the porous support membrane is simple to prepare, has good mechanical strength, good compression resistance, stable chemical properties, is nontoxic, and can resist biodegradation, so that the porous support membrane is preferably a polysulfone membrane.
In one embodiment, the pore size of the porous support membrane is 18nm to 25nm.
In one embodiment, the solvent of the oil phase solution is selected from isoparaffin solvents selected from at least one of Isopar-E, isopar-G, isopar-L; the solvent of the aqueous phase solution is water.
Meanwhile, the invention also provides a composite membrane prepared by the preparation method, which comprises a porous support membrane, an intermediate layer and a separation layer which are sequentially connected, wherein the intermediate layer is planted in the porous support membrane and extends to the surface of the porous support membrane, and the separation layer is positioned on the surface of the intermediate layer. When the composite membrane is applied to water treatment, the composite membrane has high water flux and high rejection rate.
In addition, the invention also provides application of the composite membrane in a water treatment device.
The composite membrane of the present invention is preferably used as a nanofiltration membrane in a water treatment apparatus.
In one embodiment, the water treatment device may be a seawater desalination device, wherein seawater enters from a separation layer of a composite membrane and then passes through the composite membrane under the action of pressure, wherein water molecules and monovalent ions can pass through the composite membrane, and divalent ions (such as magnesium ions) are trapped, so that seawater desalination is realized.
In one embodiment, the water treatment device may also be an underground water softening device.
Hereinafter, the composite film, and the preparation method and application thereof will be further described by the following specific examples.
The reagents, materials, and the like, which are used in the present invention, are commercially available unless otherwise specified.
Example 1
Provided is a polysulfone membrane having a pore diameter of about 20 nm.
Mixing a polyvinyl alcohol aqueous solution and sodium polyacrylate to obtain a hydrogel, wherein the mass fraction of polyvinyl alcohol in the polyvinyl alcohol aqueous solution is 0.3%, and the mass fraction of sodium polyacrylate in the hydrogel is 0.2%; mixing glutaraldehyde, sulfuric acid and water to obtain a mixed solution, wherein the mass fraction of glutaraldehyde in the mixed solution is 0.5%, and the mass fraction of sulfuric acid is 0.03%; uniformly mixing piperazine and water to obtain an aqueous phase solution, wherein the mass fraction of the piperazine in the aqueous phase solution is 0.3%; and uniformly mixing the trimesic acid chloride and Isopar-L to obtain an oil phase solution, wherein the mass fraction of the trimesic acid chloride in the oil phase solution is 0.2%.
Coating the hydrogel on the surface of a polysulfone membrane to form a hydrogel layer; coating the mixed solution on the surface of the hydrogel layer, standing for 60 seconds, pouring out the excessive mixed solution, and then placing in an oven at 80 ℃ for heat treatment for 4 minutes to form a prefabricated intermediate layer, thereby obtaining the polysulfone membrane with the prefabricated intermediate layer; immersing the polysulfone membrane with the prefabricated intermediate layer into an ammonium chloride aqueous solution, wherein the mass fraction of ammonium chloride in the ammonium chloride aqueous solution is 5%, removing sodium polyacrylate, then taking out and placing in a 100 ℃ oven for heat treatment for 2min to form the intermediate layer, and distributing a crystallization layer on the surface of the intermediate layer to obtain the polysulfone membrane with the intermediate layer; and (3) coating the oil phase solution on the surface of the middle layer far away from the polysulfone membrane, standing for 60 seconds, pouring out the excessive oil phase solution, drying the membrane surface with cold air, coating the water phase solution on the surface of the middle layer absorbing the oil phase solution, standing for 30 seconds, pouring out the excessive water phase solution, finally placing the solution into a 90 ℃ blast drying box for heat treatment for 2 minutes, and taking out to obtain the composite membrane shown in figure 1.
Example 2
Provided is a polysulfone membrane having a pore diameter of about 21 nm.
Mixing a polyvinyl alcohol aqueous solution and sodium polyacrylate to obtain a hydrogel, wherein the mass fraction of polyvinyl alcohol in the polyvinyl alcohol aqueous solution is 0.1%, and the mass fraction of sodium polyacrylate in the hydrogel is 0.1%; mixing glutaraldehyde, sulfuric acid and water to obtain a mixed solution, wherein the mass fraction of glutaraldehyde in the mixed solution is 0.1%, and the mass fraction of sulfuric acid is 0.01%; uniformly mixing piperazine and water to obtain an aqueous phase solution, wherein the mass fraction of the piperazine in the aqueous phase solution is 0.1%; and uniformly mixing the trimesic acid chloride and Isopar-L to obtain an oil phase solution, wherein the mass fraction of the trimesic acid chloride in the oil phase solution is 0.1%.
Coating the hydrogel on the surface of a polysulfone membrane to form a hydrogel layer; coating the mixed solution on the surface of the hydrogel layer, standing for 60 seconds, pouring out the excessive mixed solution, and then placing in an oven at 85 ℃ for heat treatment for 3 minutes to form a prefabricated intermediate layer, thereby obtaining the polysulfone membrane with the prefabricated intermediate layer; immersing the polysulfone membrane with the prefabricated intermediate layer into an ammonium chloride aqueous solution, wherein the mass fraction of ammonium chloride in the ammonium chloride aqueous solution is 5%, removing sodium polyacrylate, then taking out and placing in a 90 ℃ oven for heat treatment for 3min to form the intermediate layer, and distributing a crystallization layer on the surface of the intermediate layer to obtain the polysulfone membrane with the intermediate layer; and (3) coating the oil phase solution on the surface of the middle layer far away from the polysulfone membrane, standing for 60 seconds, pouring out the redundant oil phase solution, drying the membrane surface with cold air, coating the water phase solution on the surface of the middle layer absorbed with the oil phase solution, standing for 30 seconds, pouring out the redundant water phase solution, finally placing the solution into a blast drying box at 85 ℃ for heat treatment for 3 minutes, and taking out to obtain the composite membrane.
Example 3
Provided is a polysulfone membrane having a pore diameter of about 20 nm.
Mixing a polyvinyl alcohol aqueous solution and sodium polyacrylate to obtain a hydrogel, wherein the mass fraction of polyvinyl alcohol in the polyvinyl alcohol aqueous solution is 0.5%, and the mass fraction of sodium polyacrylate in the hydrogel is 0.3%; mixing glutaraldehyde, sulfuric acid and water to obtain a mixed solution, wherein the mass fraction of glutaraldehyde in the mixed solution is 1%, and the mass fraction of sulfuric acid is 0.05%; uniformly mixing piperazine and water to obtain an aqueous phase solution, wherein the mass fraction of the piperazine in the aqueous phase solution is 0.5%; and uniformly mixing the trimesic acid chloride and Isopar-L to obtain an oil phase solution, wherein the mass fraction of the trimesic acid chloride in the oil phase solution is 0.3%.
Coating the hydrogel on the surface of a polysulfone membrane to form a hydrogel layer; coating the mixed solution on the surface of the hydrogel layer, standing for 60 seconds, pouring out the excessive mixed solution, and then placing in a 90 ℃ oven for heat treatment for 3 minutes to form a prefabricated middle layer, thereby obtaining the polysulfone membrane with the prefabricated middle layer; immersing the polysulfone membrane with the prefabricated intermediate layer into an ammonium chloride aqueous solution, wherein the mass fraction of ammonium chloride in the ammonium chloride aqueous solution is 8%, removing sodium polyacrylate, then taking out and placing the polysulfone membrane in a 110 ℃ oven for heat treatment for 2min to form the intermediate layer, and distributing a crystallization layer on the surface of the intermediate layer to obtain the polysulfone membrane with the intermediate layer; and (3) coating the oil phase solution on the surface of the middle layer far away from the polysulfone membrane, standing for 60 seconds, pouring out the redundant oil phase solution, drying the membrane surface with cold air, coating the water phase solution on the surface of the middle layer absorbed with the oil phase solution, standing for 30 seconds, pouring out the redundant water phase solution, finally placing the solution into a 90 ℃ blast drying box for heat treatment for 2 minutes, and taking out to obtain the composite membrane.
Example 4
Example 4 was different from example 1 only in that the mass fraction of polyvinyl alcohol in the aqueous solution of polyvinyl alcohol was 0.8% in the preparation of the hydrogel, and the other conditions were the same, to obtain a composite film.
Example 5
Example 5 is different from example 1 only in that the mass fraction of polyvinyl alcohol in the aqueous solution of polyvinyl alcohol in the process of preparing the hydrogel was 0.05%, and the other conditions were the same, to obtain a composite film.
Example 6
Example 6 is different from example 1 only in that the mass fraction of sodium polyacrylate in the hydrogel was 0.05% in the preparation of the hydrogel, and the other conditions were the same, to obtain a composite film.
Example 7
Example 7 was different from example 1 only in that the mass fraction of sodium polyacrylate in the hydrogel was 0.6% in the preparation of the hydrogel, and the other conditions were the same, to obtain a composite film.
Example 8
Example 8 differs from example 1 only in that the mass fraction of ammonium chloride in the ammonium chloride aqueous solution was 10%, and the other conditions were the same, to obtain a composite film.
Example 9
Example 9 was different from example 1 only in that the mass fraction of ammonium chloride in the ammonium chloride aqueous solution was 1%, and the other conditions were the same, to obtain a composite film.
Example 10
Example 10 differs from example 1 only in that sodium polystyrene sulfonate was used instead of sodium polyvinyl sulfonate, and the other conditions were the same, to obtain a composite film.
Example 11
Example 11 was different from example 1 only in that glutaraldehyde was 1.5% by mass in the preparation of the mixed solution, and the other conditions were the same, to obtain a composite film.
Example 12
Example 12 is different from example 1 only in that glyoxal is used instead of glutaraldehyde and hydrochloric acid is used instead of sulfuric acid in the process of preparing a mixed solution, and in the mixed solution, the mass fraction of glyoxal is 0.1%, the mass fraction of hydrochloric acid is 0.02%, and the other conditions are the same, thereby obtaining a composite membrane.
The composite membrane of this example was tested for water flux, divalent ion rejection using a salt solution under the following conditions: the test pressure was 0.5MPa, the concentrate flow rate was 1.0GPM, the ambient temperature was 25℃and the pH of the concentrate was 6.5-7.5, the concentrate contained 2000ppm magnesium sulfate, and the test results are shown in Table 1.
Comparative example 1
Comparative example 1 was different from example 1 only in that sodium polyacrylate was not contained in the preparation of the hydrogel, that is, an aqueous polyvinyl alcohol solution was directly applied to the surface of the polysulfone membrane to form a hydrogel layer, and the other conditions were the same, to obtain a composite membrane as shown in fig. 2.
Comparative example 2
Comparative example 2 was different from example 1 only in that the polysulfone membrane with the prefabricated intermediate layer obtained in example 1 was not immersed in an aqueous ammonium chloride solution, but the oil phase solution in example 1 was applied to the surface of the prefabricated intermediate layer remote from the polysulfone membrane, left to stand for 60 seconds, the excess oil phase solution was poured off, the membrane surface was dried with cold air, then the above aqueous phase solution was applied to the surface of the intermediate layer having absorbed the oil phase solution, left to stand for 30 seconds, the excess aqueous phase solution was poured off, and finally placed in a blast drying oven at 90 ℃ for heat treatment for 2 minutes, and then taken out to obtain a composite membrane as shown in fig. 3.
Comparative example 3
Comparative example 3 was different from example 1 only in that the above aqueous phase solution was applied to the surface of the intermediate layer far from the polysulfone membrane, left to stand for 60 seconds, then the excessive aqueous phase solution was poured off, the membrane surface was dried with cold air, then the above oil phase solution was applied to the surface of the intermediate layer having absorbed the aqueous phase solution, left to stand for 30 seconds, then the excessive oil phase solution was poured off, and finally the resulting film was subjected to heat treatment in a blast drying oven at 90 deg.c for 2 minutes, to obtain a composite membrane as shown in fig. 4.
Comparative example 4
Provided is a polysulfone membrane having a pore diameter of about 20 nm.
Mixing glutaraldehyde and sulfuric acid solution to obtain a mixed solution, wherein the mass fraction of glutaraldehyde in the mixed solution is 0.5%, and the mass fraction of sulfuric acid is 0.03%; mixing the obtained mixed solution, a polyvinyl alcohol aqueous solution and sodium polyacrylate to obtain hydrogel, wherein the mass fraction of polyvinyl alcohol in the polyvinyl alcohol aqueous solution is 0.3%, and the mass fraction of sodium polyacrylate in the hydrogel is 0.2%; uniformly mixing piperazine and water to obtain an aqueous phase solution, wherein the mass fraction of the piperazine in the aqueous phase solution is 0.3%; and uniformly mixing the trimesic acid chloride and Isopar-L to obtain an oil phase solution, wherein the mass fraction of the trimesic acid chloride in the oil phase solution is 0.2%.
Coating the hydrogel on the surface of a polysulfone membrane to form a hydrogel layer; coating the mixed solution on the surface of the hydrogel layer, standing for 60 seconds, pouring out the excessive mixed solution, and then placing in an oven at 80 ℃ for heat treatment for 4 minutes to form a prefabricated intermediate layer, thereby obtaining the polysulfone membrane with the prefabricated intermediate layer; immersing the polysulfone membrane with the prefabricated intermediate layer into an ammonium chloride aqueous solution, wherein the mass fraction of ammonium chloride in the ammonium chloride aqueous solution is 5%, removing sodium polyacrylate, then taking out and placing in a 100 ℃ oven for heat treatment for 2min to form the intermediate layer, and distributing a crystallization layer on the surface of the intermediate layer to obtain the polysulfone membrane with the intermediate layer; and (3) coating the oil phase solution on the surface of the middle layer far away from the polysulfone membrane, standing for 60 seconds, pouring out the redundant oil phase solution, drying the membrane surface with cold air, coating the water phase solution on the surface of the middle layer absorbed with the oil phase solution, standing for 30 seconds, pouring out the redundant water phase solution, finally placing the solution into a 90 ℃ blast drying box for heat treatment for 2 minutes, and taking out to obtain the composite membrane.
The composite membranes of examples 1 to 12 and comparative examples 1 to 4 were tested for water flux, and divalent ion rejection, respectively, using a salt solution under the following conditions: the test pressure was 0.5MPa, the concentrate flow rate was 1.0GPM, the ambient temperature was 25℃and the pH of the concentrate was 6.5-7.5, the concentrate contained 2000ppm magnesium sulfate, and the test results are shown in Table 1.
TABLE 1
In table 1, the membrane water flux (F) is calculated from the volume of water passing through the composite membrane for a certain period of time, and the formula is: f=v/(a×t), where V is the volume of water passing through the composite membrane per unit time, a is the effective membrane area, and T is time.
The retention rate (R) is calculated by the concentration of concentrated water and the concentration of permeate, and the calculation formula is as follows: r= (1-C 1 /C 0 ) X 100%, where C 1 Is the concentration of concentrated water, C 0 Is the concentration of the permeate.
As can be seen from fig. 1, the surface of the composite membrane of example 1 of the present invention has a three-dimensional pore structure, thereby greatly increasing the water flux of the composite membrane. As can be seen from fig. 2, in comparative example 1, since sodium polyacrylate is not contained, the polyvinyl alcohol crosslinked layer and the hydrogel layer form a dense pre-made intermediate layer, resulting in a small water channel, and the ammonium chloride solution hardly enters the pre-made intermediate layer, so that a uniform crystalline layer cannot be formed, and the crystalline layer is unevenly distributed, resulting in a separation layer having protrusions in a disordered distribution on the surface thereof, and having no three-dimensional pore structure, thereby affecting the water flux of the composite membrane. As can be seen from fig. 3, in comparative example 2, since the crystallization layer cannot be formed without the ammonium chloride solution, the surface morphology of the prepared composite film is the same as that of the conventional composite film. As can be seen from fig. 4, since the aqueous phase was applied first in comparative example 3, the ammonium chloride was crystallized and dissolved, the crystalline structure was broken, and the crystals were disordered, so that the surface of the formed separation layer had a random morphology, and the increase in the specific surface area of the separation layer was not significant, resulting in a decrease in the water flux of the composite membrane.
The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.
Claims (10)
1. A method of preparing a composite membrane, comprising:
mixing a polyvinyl alcohol aqueous solution and an anionic polymer to obtain hydrogel, and then placing the hydrogel on any surface of a porous support membrane to form a hydrogel layer;
preparing a mixed solution from a cross-linking agent and an acid catalyst, placing the mixed solution on the surface of the hydrogel layer far away from the porous support membrane, and forming a prefabricated intermediate layer through first heat treatment;
placing the porous support film with the prefabricated middle layer in an ammonium chloride aqueous solution, taking out and performing second heat treatment to form a middle layer, wherein a crystallization layer is distributed on the surface of the middle layer;
and sequentially placing an oil phase solution and a water phase solution on the surface of the middle layer far away from the porous support membrane, and forming a separation layer through third heat treatment to obtain the composite membrane, wherein the oil phase solution comprises polybasic acyl chloride, and the water phase solution comprises polybasic amine.
2. The method for producing a composite film according to claim 1, wherein the mass fraction of the polyvinyl alcohol in the aqueous solution of the polyvinyl alcohol is 0.1% to 0.5%.
3. The method of preparing a composite membrane according to claim 1, wherein the mass fraction of the anionic polymer in the hydrogel is 0.1% -0.3%;
and/or the anionic polymer is at least one selected from sodium polyacrylate, anionic polyacrylamide or sodium polystyrene sulfonate.
4. The method for producing a composite film according to claim 1, wherein the mass fraction of ammonium chloride in the ammonium chloride aqueous solution is 3% -8%.
5. The method for producing a composite film according to claim 1, wherein the mass fraction of the crosslinking agent in the mixed solution is 0.1% to 1%;
and/or the cross-linking agent is dialdehyde, and the dialdehyde is at least one selected from glutaraldehyde, glyoxal, malondialdehyde and succinaldehyde;
and/or the mass fraction of the acid catalyst in the mixed solution is 0.01% -0.05%;
and/or the acid catalyst is selected from inorganic acid, and the inorganic acid is at least one of hydrochloric acid, sulfuric acid, nitric acid, perchloric acid, hydrobromic acid, permanganic acid and hydroiodic acid.
6. The method for producing a composite film according to any one of claims 1 to 5, wherein the mass fraction of the polyamine in the aqueous phase solution is 0.1% to 0.5%;
and/or the polyamine is at least one selected from piperazine, polyethyleneimine, m-phenylenediamine, p-phenylenediamine and tetraethylenepentamine.
7. The method for producing a composite film according to any one of claims 1 to 5, wherein the mass fraction of the polyacyl chloride in the oil phase solution is 0.1% to 0.3%;
and/or the polybasic acyl chloride is selected from at least one of trimesoyl chloride, isophthaloyl chloride and terephthaloyl chloride.
8. The method for producing a composite film according to any one of claims 1 to 5, wherein the first heat treatment temperature is 60 ℃ to 90 ℃, and the first heat treatment time is 3min to 5min;
and/or the second heat treatment temperature is 70-110 ℃, and the second heat treatment temperature is 2-3 min;
and/or the third heat treatment temperature is 70-95 ℃, and the third heat treatment temperature is 2-3 min.
9. A composite film prepared by the method of any one of claims 1 to 8.
10. Use of the composite membrane of claim 9 in a water treatment device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410141028.0A CN117654287A (en) | 2024-02-01 | 2024-02-01 | Composite membrane and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410141028.0A CN117654287A (en) | 2024-02-01 | 2024-02-01 | Composite membrane and preparation method and application thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117654287A true CN117654287A (en) | 2024-03-08 |
Family
ID=90068381
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202410141028.0A Pending CN117654287A (en) | 2024-02-01 | 2024-02-01 | Composite membrane and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117654287A (en) |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006320896A (en) * | 2005-04-22 | 2006-11-30 | Asahi Kasei Chemicals Corp | Compound membrane, and its manufacturing method |
| CN105771703A (en) * | 2016-03-15 | 2016-07-20 | 北京工业大学 | Preparation method of polyethersulfone-based composite positive permeable membrane |
| CN108211826A (en) * | 2018-02-13 | 2018-06-29 | 温州莲华环保科技有限公司 | A kind of forward osmosis membrane and preparation method thereof |
| CN108889139A (en) * | 2018-07-31 | 2018-11-27 | 南京工业大学 | A method of high-throughput covalent organic framework nanofiltration membrane is prepared based on interfacial polymerization |
| US20210245111A1 (en) * | 2018-04-23 | 2021-08-12 | Korea University Research And Business Foundation | Technique for manufacturing high solute-selective thin film composite membranes using aromatic hydrocarbon solvents |
| CN114642968A (en) * | 2020-12-18 | 2022-06-21 | 中国科学院苏州纳米技术与纳米仿生研究所 | High-flux composite nanofiltration membrane with soluble intermediate layer, and preparation method and application thereof |
| CN115672066A (en) * | 2022-10-20 | 2023-02-03 | 山东大学 | Method for preparing nanofiltration membrane of thin polyamide layer based on hydrogel intermediate layer |
| US20230059166A1 (en) * | 2021-07-14 | 2023-02-23 | Avanpore LLC | Composite Poly (Aryl Ether Ketone) Membranes, Their Preparation And Use Thereof |
| CN115888441A (en) * | 2023-01-06 | 2023-04-04 | 湖南沁森高科新材料有限公司 | Composite nanofiltration membrane and preparation method thereof |
| CN116459684A (en) * | 2023-06-19 | 2023-07-21 | 蓝星（杭州）膜工业有限公司 | Composite membrane and preparation method and application thereof |
| CN117225194A (en) * | 2023-11-01 | 2023-12-15 | 哈尔滨工业大学 | Preparation method of high-flux scale-inhibiting anti-wetting composite distillation membrane |
-
2024
- 2024-02-01 CN CN202410141028.0A patent/CN117654287A/en active Pending
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006320896A (en) * | 2005-04-22 | 2006-11-30 | Asahi Kasei Chemicals Corp | Compound membrane, and its manufacturing method |
| CN105771703A (en) * | 2016-03-15 | 2016-07-20 | 北京工业大学 | Preparation method of polyethersulfone-based composite positive permeable membrane |
| CN108211826A (en) * | 2018-02-13 | 2018-06-29 | 温州莲华环保科技有限公司 | A kind of forward osmosis membrane and preparation method thereof |
| US20210245111A1 (en) * | 2018-04-23 | 2021-08-12 | Korea University Research And Business Foundation | Technique for manufacturing high solute-selective thin film composite membranes using aromatic hydrocarbon solvents |
| CN108889139A (en) * | 2018-07-31 | 2018-11-27 | 南京工业大学 | A method of high-throughput covalent organic framework nanofiltration membrane is prepared based on interfacial polymerization |
| CN114642968A (en) * | 2020-12-18 | 2022-06-21 | 中国科学院苏州纳米技术与纳米仿生研究所 | High-flux composite nanofiltration membrane with soluble intermediate layer, and preparation method and application thereof |
| US20230059166A1 (en) * | 2021-07-14 | 2023-02-23 | Avanpore LLC | Composite Poly (Aryl Ether Ketone) Membranes, Their Preparation And Use Thereof |
| CN115672066A (en) * | 2022-10-20 | 2023-02-03 | 山东大学 | Method for preparing nanofiltration membrane of thin polyamide layer based on hydrogel intermediate layer |
| CN115888441A (en) * | 2023-01-06 | 2023-04-04 | 湖南沁森高科新材料有限公司 | Composite nanofiltration membrane and preparation method thereof |
| CN116459684A (en) * | 2023-06-19 | 2023-07-21 | 蓝星（杭州）膜工业有限公司 | Composite membrane and preparation method and application thereof |
| CN117225194A (en) * | 2023-11-01 | 2023-12-15 | 哈尔滨工业大学 | Preparation method of high-flux scale-inhibiting anti-wetting composite distillation membrane |
Non-Patent Citations (2)
| Title |
|---|
| 付轲;沈利燕;李丹丹;计剑;: "双网络增强自支撑多层膜的制备", 高分子学报, no. 08, 20 August 2011 (2011-08-20) * |
| 杨寅;李雄;神领弟;王敏;王雪芬;朱美芳;: "卡波普改性纳米纤维基复合纳滤膜的结构与性能", 高分子学报, no. 04, 20 April 2014 (2014-04-20) * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5978998B2 (en) | Composite semipermeable membrane, composite semipermeable membrane element, and method for producing composite semipermeable membrane | |
| US9827536B2 (en) | Composite semipermeable membrane | |
| CN111225735A (en) | Selectively permeable graphene oxide membranes | |
| CN110545903B (en) | Membrane permeability-enhanced thin film composite membranes with nano-sized bubbles, methods of making and uses thereof | |
| CN102105214A (en) | Composite semipermeable membrane and manufacturing method therefor | |
| WO2012102678A1 (en) | A forward osmosis membrane | |
| JP6052172B2 (en) | Manufacturing method of composite semipermeable membrane | |
| CN111408281B (en) | Composite forward osmosis membrane and preparation method thereof | |
| CN111686594B (en) | High-flux high-rejection composite membrane and preparation method thereof | |
| WO1999020378A1 (en) | A manufacturing method of composite membrane having hydrophilic coating layer on hydrophobic support membrane | |
| CN114534491B (en) | Reverse osmosis membrane with high water flux and preparation method and application thereof | |
| TW201932189A (en) | Composite hollow fiber membrane, and method for producing composite hollow fiber membrane | |
| JP2001513437A (en) | Polyion complex separation membrane with double structure | |
| EP3589389A1 (en) | Selectively permeable graphene oxide membrane | |
| CN112973460B (en) | Crosslinked covalent organic framework desalting membrane and preparation method and application thereof | |
| CN114191992A (en) | Composite nanofiltration membrane for extracting lithium from salt lake and preparation method thereof | |
| US20240024827A1 (en) | Preparation method of reverse osmosis composite membrane and reverse osmosis composite membrane prepared thereby | |
| CN117654287A (en) | Composite membrane and preparation method and application thereof | |
| KR20120077997A (en) | Manufacturing method for polyamide-based reverse osmosis membrane and polyamide-based reverse osmosis membrane manufactured thereby | |
| CN113750818B (en) | High-permeability polyamide reverse osmosis composite membrane and preparation method thereof | |
| CN117654288B (en) | Composite membrane and preparation method and application thereof | |
| CN117138577A (en) | Nanofiltration membrane with silanol three-dimensional network interlayer and preparation method thereof | |
| CN115608168A (en) | Composite film with high boron removal rate and preparation method thereof | |
| CN116212636A (en) | Nanofiltration membrane and preparation method thereof | |
| CN117839458A (en) | Composite membrane and preparation method and application 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 |