A high-organic-rejection anti-fouling polyamide reverse osmosis membrane, a preparation method and application thereof

Abstract

The application discloses a kind of high organic matter removal anti-pollution polyamide reverse osmosis membrane and its preparation method and application, the polyamide reverse osmosis membrane, polyester non-woven fabric layer, polysulfone ultrafiltration support layer, polyamide separation bottom membrane layer and hydrophilic polymer anti-pollution layer are included in sequence;The polyamide separation bottom membrane layer is the crosslinked polymer formed by the interfacial polycondensation reaction of polyamine and polyacyl chloride;The hydrophilic polymer anti-pollution layer is the polymer formed by the crosslinking reaction of diblock hydrophilic polymer comprising pyrrolidone segment and amino segment and small molecular compound comprising epoxy group and / or allyl group.The polyamide reverse osmosis membrane of the application has good application prospect in the field such as organic matter removal in electronic industry pure water, trace organic matter removal in domestic drinking water and the like.

Description

Technical Field

[0001] This invention relates to the field of reverse osmosis technology, and in particular to a fouling-resistant polyamide reverse osmosis membrane with high organic matter removal, its preparation method, and its application. Background Technology

[0002] Currently, polyamide reverse osmosis membrane technology, as a highly efficient, affordable, and mainstream separation technology, is widely used in seawater desalination, brackish water desalination, industrial wastewater treatment, municipal sewage treatment, household water purification, and industrial pure water production. In the electronics industry, the pure water produced requires the use of polyamide reverse osmosis membranes to remove some small-molecule organic matter. Based on the current production processes and techniques in the electronics industry, it can be confirmed that the organic matter present in pure water includes alcohols, aldehydes, carboxylic acids, and some small-molecule organic compounds containing amino groups. During the use of reverse osmosis membranes, due to the deposition and adsorption of these organic substances, as well as their chemical interactions with the membrane surface during mechanical, physical, or filtration processes, membrane fouling occurs on the reverse osmosis membrane surface, leading to a reduction in reverse osmosis water production. Because reverse osmosis membranes in the electronics industry cannot be periodically cleaned with acids and alkalis like those in wastewater treatment or seawater desalination to remove residual contaminants and restore membrane water production, this process is problematic. Therefore, it is very important to develop a fouling-resistant reverse osmosis membrane with low flux decline and high acid and alkali cleaning recovery rate during operation. This is of great significance for reducing the frequency of acid and alkali cleaning, improving the membrane permeate recovery rate after cleaning, and extending the service life of the reverse osmosis membrane.

[0003] In terms of improving the antifouling performance of reverse osmosis membranes, current literature and patents mainly focus on improving the hydrophilicity of the reverse osmosis membrane surface, reducing the surface roughness of the membrane, and making the membrane surface closer to electrical neutrality.

[0004] There are few existing studies on improving the acid and alkali cleaning resistance of reverse osmosis membranes, and most of them focus on the control of interfacial polymerization process and chemical post-treatment.

[0005] Polyvinylpyrrolidone (PVP) is a more chemically stable and biocompatible hydrophilic polymer compared to traditional hydrophilic polymers (such as polyvinyl alcohol and polyethylene glycol). When PPVP is modified onto a coating surface, its intrachain hydrophilic pyrrolidone units can bind water molecules to form a hydration layer, effectively eliminating electrostatic and hydrophobic interactions between biomolecules and the material surface, thus creating a stable anti-bioadhesion interface.

[0006] Because polyvinylpyrrolidone (PVP) lacks reaction sites on its molecular structure that can interact with the groups (amino, amide, and carboxyl) on the polyamide layer, it is difficult for PPVP to chemically bond to the membrane surface. Currently, PPVP is mainly applied to the polyamide layer in three ways. The first method is direct physical coating onto the polyamide layer surface. For example, Chinese invention patent CN201480043520 discloses a method for preparing antifouling reverse osmosis membranes by directly coating a PPVP solution and then drying it in an oven. However, since PPVP only interacts with the membrane surface through hydrogen bonds, it is prone to detachment during actual operation. The second method involves constructing an intermediate layer on the surface of the polyamide layer and then coating it with polyvinylpyrrolidone (PVP). For example, Chinese invention patent CN201510166251 discloses a method that uses tannic acid and ferric chloride to form a complex intermediate layer on the surface of the polyamide layer, and then introduces PPVP onto the surface of the reverse osmosis membrane. The prepared antifouling membrane has good antifouling performance against pollutants such as proteins and polysaccharides. Although there is a strong hydrogen bond between the complex and PPVP, the PPVP layer still detaches after repeated acid and alkali cleaning in actual operation. The third method involves adding vinylpyrrolidone monomer to the aqueous phase and photo-initiating polymerization to form a PPVP antifouling layer, or using a photoinitiator and ultraviolet irradiation to graft PPVP onto the surface of the polyamide layer. For example, Chinese invention patent CN201910016832 discloses a method that adds vinylpyrrolidone to an aqueous solution, performs interfacial polymerization, and then treats it with gamma rays to obtain an antifouling reverse osmosis membrane with relatively excellent antifouling performance. Although this method forms chemical bonds, gamma-ray irradiation is dangerous and time-consuming, making its application in actual production processes difficult. Chinese invention patent CN202010392827 discloses a method that uses ultraviolet irradiation to polymerize polyvinylpyrrolidone (PVP) with carbon-carbon double bonds in a polyamide layer under the action of a photoinitiator benzophenone, thereby fixing PPVP onto the surface of a polyamide membrane. This method improves the antifouling performance and desalination rate of the prepared reverse osmosis membrane. Adding vinylpyrrolidone to an aqueous solution, followed by interfacial polymerization and gamma-ray irradiation, yields an antifouling reverse osmosis membrane with excellent antifouling properties. While this method is relatively convenient to implement in actual production, the use of a 1:1 mixture of water and methanol as solvent still poses a relatively high risk during production.

[0007] Therefore, there is a need in the art to develop a method that can efficiently and conveniently link polyvinylpyrrolidone to the surface of a reverse osmosis membrane with strong chemical bonds to form an antifouling layer. Summary of the Invention

[0008] To address the problems existing in the prior art, this invention provides a simple and suitable method for preparing an antifouling polyamide reverse osmosis membrane with high organic matter removal efficiency for continuous industrial production. This method improves the antifouling performance and cleaning and recovery performance of existing reverse osmosis membranes, while also enhancing the membrane's ability to remove trace organic matter from water.

[0009] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0010] In a first aspect, the present invention provides a high organic matter removal antifouling polyamide reverse osmosis membrane, comprising, in sequence, a polyester nonwoven fabric layer, a polysulfone ultrafiltration support layer, a polyamide separation bottom membrane layer, and a hydrophilic polymer antifouling layer;

[0011] The polyamide separation bottom membrane layer is a cross-linked polymer formed by the interfacial polycondensation reaction of polyamines and polyacryl chlorides;

[0012] The hydrophilic polymer antifouling layer is a polymer formed by cross-linking a diblock hydrophilic polymer containing pyrrolidone segments and amino segments with a small molecule compound containing epoxy groups and / or allyl groups.

[0013] In one embodiment, after the polyamide separation substrate layer is constructed in situ on the membrane surface of the polysulfone ultrafiltration support layer, a diblock hydrophilic polymer containing pyrrolidone segments and amino segments is first grafted onto the polyamide separation substrate layer, and then crosslinked with a small molecule compound containing epoxy groups and / or allyl groups to form the hydrophilic polymer antifouling layer.

[0014] In their research on polyamide reverse osmosis membranes, the inventors of this application unexpectedly discovered that by grafting a hydrophilic polymer onto the nascent polyamide layer and then crosslinking it with a small molecule compound containing epoxy or allyl groups, the initial properties of the membrane, such as flux and desalination rate, did not decrease significantly. Furthermore, the membrane exhibited more robust and long-lasting antifouling properties, and the removal rate of trace organic matter (such as alcohols, amines, ketones, and organic acids) from the water was significantly improved.

[0015] The possible mechanism of action of the technical solution of this invention is analyzed as follows: First, the hydrophilic polymer reacts with the residual acyl chloride on the nascent polyamide layer through the amino groups in its molecules, and is connected to the surface of the polyamide layer through the formed amide bonds. Due to the large molecular weight and certain flexibility of the hydrophilic polymer, some hydrophilic polymer segments will embed into the interior of the polyamide layer, crosslinking the polyamide layer. Subsequently, small molecules containing epoxy or allyl groups react with the residual amino groups in the hydrophilic polymer and the residual amino groups in the polyamide layer to form a crosslinked antifouling layer. Because the antifouling layer contains a large number of hydrophilic groups, it can avoid the significant reduction in flux caused by other antifouling coating polymers. More importantly, the antifouling layer is chemically bonded, and the antifouling layer is a crosslinked structure that is not easy to fall off. After multiple acid and alkali washings, it can still maintain high antifouling performance, and at the same time, the removal rate of trace organic matter (such as alcohols, amines, ketones, and organic acids) in water is significantly improved.

[0016] In some embodiments, the polyester nonwoven layer is made of materials including, but not limited to, any one or a mixture of several of polyethylene terephthalate, polypropylene terephthalate and polybutylene terephthalate.

[0017] More preferably, the polyester nonwoven fabric is polyethylene terephthalate nonwoven fabric.

[0018] In some embodiments, the polysulfone ultrafiltration support layer is a porous ultrafiltration membrane formed by coating a polyester nonwoven fabric layer with polysulfone material, the pore size of which ranges from 1 to 100 nm, preferably from 1 to 50 nm; and the thickness of which ranges from 20 to 150 μm, preferably from 30 to 80 μm.

[0019] In some embodiments, the polyamine is an aromatic amine or an aliphatic amine containing at least two primary amino groups; preferably, the aromatic amine includes, but is not limited to, any one or a mixture of several of phenylenediamine or phenylenedimethylamine, 1,3,5-triaminobenzene bonded to the benzene ring at the ortho, meta, or para positions, and the aliphatic amine includes, but is not limited to, any one or a mixture of several of ethylenediamine, propylenediamine, and piperazine.

[0020] More preferably, the polyfunctional amine is m-phenylenediamine.

[0021] In some embodiments, the polyacryl chloride is selected from aromatic and / or aliphatic polyacryl chlorides; preferably, the aromatic polyacryl chloride includes, but is not limited to, any one or a mixture of several of pyromellitic tricarboxylic acid chloride, terephthaloyl chloride, isophthaloyl chloride, and naphthiadicarboxylic acid chloride, and the aliphatic polyacryl chloride includes, but is not limited to, any one or a mixture of several of malonyl chloride, succinyl chloride, adipic acid chloride, and 1,4-cyclohexamethylenedicarboxylic acid chloride;

[0022] More preferably, the polyacrylamide chloride is pyromellitic trimethylolpropionate chloride.

[0023] In some embodiments, the diblock hydrophilic polymer comprising pyrrolidone and amino segments has a weight-average molecular weight ranging from 20,000 to 150,000 Da, preferably from 40,000 to 80,000 Da; its weight-average molecular weight and molecular weight distribution (PDI) range from 1 to 5, preferably from 1 to 3; and its actual pyrrolidone / amino molar ratio ranges from 2 to 20, preferably from 3 to 10.

[0024] In some embodiments, the diblock hydrophilic polymer comprising pyrrolidone segments and amino segments is a diblock copolymer synthesized by free radical copolymerization, wherein the monomers include pyrrolidone-containing monomers and amino-containing monomers.

[0025] Preferably, the pyrrolidone-containing monomer includes, but is not limited to, any one or a mixture of several of vinylpyrrolidone, 3-allylpyrrolidone-2-one, 3-(2-methylprop-2-enyl)pyrrolidone-2-one, 3-(3-buten-1-yl)-2-pyrrolidone, 3-(3-buten-1-yl)-3-(2-propen-1-yl)-2-pyrrolidone, and 1-(1-propenyl)pyrrolidone-2-one, more preferably vinylpyrrolidone;

[0026] Preferably, the amino-containing monomer includes, but is not limited to, any one or a mixture of several of N-methylallylamine, diallylamine, allylethylamine, 2-methylpropenamine, N-ethylmethylpropenamine, and allylamine, and more preferably, any one or a mixture of several of N-methylallylamine and diallylamine.

[0027] In actual operation, the pyrrolidone-containing monomer and the amino-containing monomer can be fed in any positive ratio. Preferably, the mass ratio of the pyrrolidone-containing monomer and the amino-containing monomer is 95:5 to 75:25.

[0028] The free radical copolymerization method described above involves reacting to synthesize diblock copolymers in the presence of an initiator. The initiator is selected from any one or a mixture of several of azobisisobutyronitrile, azobisisoheptanenitrile, and benzoyl peroxide, preferably azobisisobutyronitrile.

[0029] The amount of initiator used is 0.01 to 5.0% of the total mass of the pyrrolidone monomer and the amino monomer, preferably 0.5 to 2.0%.

[0030] The free radical copolymerization method described above involves reacting and synthesizing diblock copolymers in a solvent environment. The solvent is selected from any one or a mixture of several of N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, tetrahydrofuran, ethylene glycol methyl ether, diethylene glycol dimethyl ether, ethyl acetate, dioxane, and pyridine, preferably N-methylpyrrolidone.

[0031] The amount of solvent used accounts for 20-99% of the total mass of the reaction system, more preferably 40-80%.

[0032] The free radical copolymerization method described above is a known process in the prior art. The relevant operations and process conditions in the preparation method of this invention, as well as the apparatus used, can all be carried out using conventional methods in the art, and there are no particular restrictions. Those skilled in the art can optimize the process based on existing known processes according to actual needs, for example:

[0033] The free radical copolymerization method described herein has a reaction temperature of 50–100°C, preferably 70–90°C, and a reaction time of 0.5–24 hours, preferably 4–8 hours.

[0034] In some embodiments, the small molecule compounds comprising epoxy and / or allyl groups include, but are not limited to, any one or a mixture of several of polyethylene glycol diglycidyl ether, ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, bisphenol A diglycidyl ether, trimethylolpropane triglycidyl ether, allyl glycidyl ether, and reactive allyl epoxy polyether, preferably any one or a mixture of several of polyethylene glycol diglycidyl ether, allyl glycidyl ether, and reactive allyl epoxy polyether.

[0035] Secondly, the present invention provides a method for preparing the above-mentioned antifouling polyamide reverse osmosis membrane with high organic matter removal, which can be prepared by combination screening based on conventional processes in the field, according to the actual required structure.

[0036] Specifically, a method for preparing a fouling-resistant polyamide reverse osmosis membrane with high organic matter removal capability includes the following steps:

[0037] S1: Obtain a polysulfone ultrafiltration support layer on the surface of a polyester nonwoven fabric layer;

[0038] S2: Immerse the polysulfone ultrafiltration support layer in an aqueous solution containing polyamines and additives, leave it for a period of time, and then remove the residual aqueous solution from the surface.

[0039] S3: The surface of the polysulfone ultrafiltration support layer is brought into contact with an organic phase solution containing polyacrylamide chloride to carry out an interfacial polymerization reaction. After reacting for a period of time, the residual organic phase solution on the surface is removed, followed by heat treatment, and then water washing until the membrane surface is hydrophilic (i.e. no droplet aggregation on the membrane surface) to form a polyamide separation bottom membrane layer.

[0040] S4: The surface of the polyamide separation substrate layer is brought into contact with an aqueous solution containing a diblock hydrophilic polymer containing pyrrolidone segments and amino segments and a surfactant to carry out a grafting reaction. After reacting for a period of time, the residual aqueous solution on the surface is removed, and then the surface is rinsed with water to obtain a polyamide separation substrate layer grafted with hydrophilic polymer.

[0041] S5: The surface of the polyamide separation bottom membrane layer grafted with hydrophilic polymer is brought into contact with an aqueous solution containing small molecule compounds including epoxy groups and / or allyl groups for thermal crosslinking reaction. After reacting for a period of time, the residual aqueous solution on the surface is removed, and then the membrane is rinsed with water to obtain the antifouling polyamide reverse osmosis membrane with high organic matter removal.

[0042] In the preparation method of this invention, the raw material selection listed above can be referred to. For other related operations and process conditions, as well as the equipment used, conventional selections in the art can be adopted, and there are no particular restrictions. Those skilled in the art can optimize the process based on existing technology and known processes according to actual needs. Specifically, for example, the conditions listed in the following embodiments of this invention can be used:

[0043] In some embodiments, the concentration of the polyamine in the aqueous solution described in step S2 is 0.5 to 10.0 wt%, preferably 1.0 to 5.0 wt%.

[0044] Preferably, the concentration of the additive in the aqueous solution is 1.0 to 20.0 wt%.

[0045] In some preferred embodiments, the pH of the aqueous solution is 9.0 to 12.0.

[0046] In one specific embodiment, the aqueous solution contains an additive, which is an acid receiver selected from weak bases, buffer pairs composed of weak bases and acids, or any one or a mixture of alkali metal hydroxides, carbonates and bicarbonates, and organic acid salts (such as one or a mixture of sulfonic acids and carboxylic acids).

[0047] Preferably, the weak base is selected from triethylamine and sodium phosphate, or a mixture of several of these; the buffer pair formed by the weak base and acid is selected from triethylamine hydrochloride and triethylamine camphor sulfonate, or a mixture of several of these; the alkali metal hydroxide, carbonate, and bicarbonate are selected from sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate, or a mixture of several of these; and the organic compound is selected from tetramethylammonium hydroxide and tetraethylammonium hydroxide, or a mixture of several of these.

[0048] More preferably, the acid receiver is triethylamine camphor sulfonate.

[0049] In a preferred embodiment, the aqueous solution contains 1.1 to 3.5 wt% triethylamine and 2.3 to 6.5 wt% camphor sulfonic acid.

[0050] In some implementations, the dwell time described in step S2 is 10 to 120 seconds.

[0051] In some embodiments, the concentration of polyacrylamide chloride in the organic phase solution described in step S3 is 0.01–1.0 wt%, preferably 0.05–0.5 wt%.

[0052] In some embodiments, the solvent in the organic phase solution described in step S3 is selected from any one or a mixture of several of n-hexane, cyclohexane, n-heptane, n-decane, isoalkanes Isopar G, and isoalkanes Isopar L, preferably any one or a mixture of several of n-hexane, cyclohexane, and isoalkanes Isopar G.

[0053] In some embodiments, the interfacial polymerization reaction described in step S3 is carried out at a temperature of 10–50°C, preferably 15–35°C, for a time of 10–60 seconds, preferably 30–60 seconds.

[0054] In some embodiments, the heat treatment in step S3 is performed at a temperature of 50–120°C, preferably 60–100°C, for a time of 3–10 minutes, preferably 3–5 minutes.

[0055] In some embodiments, the concentration of the diblock hydrophilic polymer comprising pyrrolidone segments and amino segments in the aqueous solution described in step S4 is 0.01 to 10.0 wt%, preferably 0.05 to 1.0 wt%.

[0056] Preferably, the concentration of the surfactant in the aqueous solution is 0.01–10.0 wt%, more preferably 0.10–1.0 wt%.

[0057] In some embodiments, the aqueous solution described in step S4 contains a surfactant selected from sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, hexadecyl ammonium bromide, dodecyl trimethyl ammonium bromide, dodecyl dimethyl benzyl ammonium bromide, tetrabutyl ammonium bromide, cocoyl glucoside, lauryl glucoside, sucrose esters, polysorbates (Tween), polyoxyethylene derivatives, polyoxyethylene-polyoxypropylene copolymers, and polyvinylpyrrolidone, preferably selected from sodium dodecyl sulfate, polyvinylpyrrolidone, and Tween 80, or a mixture of several of these surfactants.

[0058] In some embodiments, the grafting reaction described in step S4 is carried out at a temperature of 10–60°C, preferably 20–40°C, and for a reaction time of 10–600 seconds, preferably 30–180 seconds.

[0059] In some embodiments, the concentration of the small molecule compound containing epoxy and / or allyl groups in the aqueous solution described in step S5 is 0.01 to 2.0 wt%, preferably 0.05 to 0.5 wt%.

[0060] In some embodiments, the thermal crosslinking reaction described in step S5 is carried out at a temperature of 50–100°C, preferably 60–90°C, and for a reaction time of 30–600 seconds, preferably 60–300 seconds.

[0061] Thirdly, the present invention also provides the use of the above-mentioned antifouling polyamide reverse osmosis membrane for removing high organic matter.

[0062] The antifouling polyamide reverse osmosis membrane with high organic matter removal capability described in this invention has advantages such as low flux loss, high desalination rate, and antifouling properties. Specifically, the flux loss is less than 20%, the desalination rate can reach over 99.3%, and the removal rate of trace organic matter (such as isopropanol) in water can be higher than 90%. The reverse osmosis membrane with high organic matter removal capability is used in water treatment components or water treatment methods, wherein the reverse osmosis membrane is prepared by the above method or is the reverse osmosis membrane described above.

[0063] The water treatment component can be any component or device that can be applied to a water treatment process and is equipped with the reverse osmosis membrane of the present invention, including components or devices used in the preparation of such components or devices; the component can be, for example, a spiral wound membrane module and a disc tube flat sheet membrane module, or a household / commercial reverse osmosis water purifier, an industrial boiler feedwater reverse osmosis pure water device, an industrial wastewater reuse reverse osmosis device, etc.; the water treatment method can be, for example, brackish water wastewater reuse, drinking water production, removal of trace organic matter from pure water and drinking water, etc.

[0064] Compared with the prior art, the beneficial effects of the present invention are reflected in:

[0065] 1) This invention provides a high organic matter removal antifouling polyamide reverse osmosis membrane with low flux loss and high desalination rate, while also maintaining stable and long-lasting antifouling performance.

[0066] 2) The hydrophilic antifouling layer of the polyamide reverse osmosis membrane of this invention has a chemically cross-linked structure, which is chemically bonded to the polyamide layer, making its structure more stable and maintaining high antifouling performance even after multiple acid and alkali cleanings. At the same time, this chemical cross-linking further cross-links the interior of the polyamide as well as the polyamide and the antifouling layer, improving the removal rate of trace organic matter in the water.

[0067] 3) The hydrophilic polymer in the polyamide reverse osmosis membrane of this invention is produced by free radical copolymerization, eliminating the need for subsequent separation and purification processes. This results in simple operation and low production costs. Furthermore, the grafting process of the hydrophilic polymer antifouling layer does not require modification of the existing process, making it easy for industrial production. Detailed Implementation

[0068] To better understand the technical solution of the present invention, the following embodiments will further illustrate the method provided by the present invention. However, the present invention is not limited to the listed embodiments, but should also include any other known modifications within the scope of the claims of the present invention.

[0069] A high organic matter removal antifouling polyamide reverse osmosis membrane, comprising, in sequence, a polyester nonwoven fabric layer, a polysulfone ultrafiltration support layer, a polyamide separation bottom membrane layer in situ constructed on the polysulfone ultrafiltration support layer, and a hydrophilic polymer antifouling layer.

[0070] The present invention relates to a high-organic-removal, fouling-resistant polyamide reverse osmosis membrane, wherein the polysulfone ultrafiltration support layer is a polysulfone ultrafiltration membrane layer formed on the surface of a polyester nonwoven fabric layer. The preparation of the polysulfone ultrafiltration support layer can employ existing well-known techniques in the art, and no limitation is made thereto.

[0071] In a preferred embodiment, the polysulfone ultrafiltration support layer has a pore size range of 1–100 nm, preferably 1–50 nm; its thickness ranges from 20–150 μm, preferably 30–80 μm; specifically, the pore size can be 1 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, or any combination thereof; the thickness can be 20 μm, 40 μm, 60 μm, 80 μm, 100 μm, 120 μm, 140 μm, 150 μm, or any combination thereof.

[0072] In a preferred embodiment, the polymer solution for preparing the polysulfone ultrafiltration support layer may contain 15.0–20.0 wt% polysulfone resin. These components are dissolved in a polar solvent to obtain a polysulfone casting solution. Specifically, the concentration of polysulfone resin in the polymer solution may be 15.0 wt%, 15.4 wt%, 16.0 wt%, 16.5 wt%, 17.0 wt%, 17.5 wt%, 18.0 wt%, 18.5 wt%, 19.0 wt%, 19.5 wt%, 20.0 wt%, or any combination thereof. The filtered and degassed polysulfone casting solution is then coated onto the surface of a polyester nonwoven fabric (e.g., polyethylene terephthalate nonwoven fabric). The film is then placed in a gel bath for phase inversion to form a membrane. After washing, the polysulfone ultrafiltration support layer is obtained. The polar solvent preferably includes one or more of N,N-dimethylformamide, N,N-dimethylacetamide, or N-methylpyrrolidone.

[0073] The polyamide separation membrane layer in situ constructed on the polysulfone ultrafiltration support layer of the present invention can be prepared using existing well-known techniques in the art, and is not particularly limited thereto. In a preferred embodiment, the polyamide separation membrane layer in situ constructed on the polysulfone ultrafiltration support layer is a cross-linked aromatic polyamide primary layer with a three-dimensional network structure formed by interfacial polycondensation of polyamines (e.g., m-phenylenediamine) and polyacrylamide chlorides (e.g., trimesoyl pyromellitic acid chloride).

[0074] The hydrophilic polymer antifouling layer of the present invention is prepared by a stepwise grafting method. First, a diblock hydrophilic polymer containing pyrrolidone segments and amino segments is grafted, and then crosslinked by small molecule compounds containing epoxy groups and / or allyl groups to form a hydrophilic polymer antifouling layer. After washing with water, an antifouling polyamide reverse osmosis membrane with high organic matter removal is obtained.

[0075] A method for preparing a fouling-resistant polyamide reverse osmosis membrane with high organic matter removal capacity includes the following steps:

[0076] S1: Coating the surface of the polyester nonwoven fabric layer with polysulfone material and obtaining the polysulfone ultrafiltration support layer through phase inversion;

[0077] S2: Immerse the polysulfone ultrafiltration support layer in an aqueous solution containing polyamines and additives, leave it for a period of time, and then remove the residual aqueous solution from the surface.

[0078] S3: The surface of the polysulfone ultrafiltration support layer is brought into contact with an organic phase solution containing polyacrylamide chloride to carry out an interfacial polymerization reaction. After reacting for a period of time, the residual organic phase solution on the surface is removed, followed by heat treatment, and then water washing until the membrane surface is hydrophilic (no droplet aggregation) to form a polyamide separation bottom membrane layer.

[0079] S4: The surface of the polyamide separation substrate layer is brought into contact with an aqueous solution containing a diblock hydrophilic polymer containing pyrrolidone segments and amino segments and a surfactant to carry out a grafting reaction. After reacting for a period of time, the residual aqueous solution on the surface is removed, and then the surface is rinsed with water to obtain a polyamide separation substrate layer grafted with hydrophilic polymer.

[0080] S5: The surface of the polyamide separation bottom membrane layer grafted with hydrophilic polymer is brought into contact with an aqueous solution containing small molecule compounds including epoxy groups and / or allyl groups for thermal crosslinking reaction. After reacting for a period of time, the residual aqueous solution on the surface is removed, and then the membrane is rinsed with water to obtain the antifouling polyamide reverse osmosis membrane with high organic matter removal.

[0081] In the preparation method of the present invention, the base membrane layer with polysulfone ultrafiltration support layer on the surface obtained in step S1 can be prepared by referring to the methods listed above. For other raw material selection, related operations and process conditions, and the equipment used, the corresponding conventional selections in the field can be adopted. There are no special restrictions. Those skilled in the art can optimize the process based on existing technology and known processes according to actual needs. The present invention will not elaborate further here.

[0082] The polyamide separation substrate layer of the present invention is a cross-linked polymer formed by interfacial polyamine and polyacryl chloride through interfacial polycondensation.

[0083] In a preferred embodiment, the polyamine in step S2 is an aromatic amine or an aliphatic amine containing at least two primary amine groups; preferably, the aromatic amine includes, but is not limited to, any one or a mixture of several of phenylenediamine or phenylenediamine, and 1,3,5-triaminobenzene bonded to the benzene ring at the ortho, meta, and para positions; the aliphatic amine includes, but is not limited to, any one or a mixture of several of ethylenediamine, propylenediamine, and piperazine; more preferably, the polyfunctional amine is m-phenylenediamine;

[0084] In the aqueous solution, the concentration of the polyamine is 0.5 to 10.0 wt%, preferably 1.0 to 5.0 wt%; specifically, the concentration of the polyamine can be 0.5 wt%, 1.0 wt%, 2.0 wt%, 3.0 wt%, 4.0 wt%, 5.0 wt%, 6.0 wt%, 7.0 wt%, 8.0 wt%, 9.0 wt%, 10.0 wt%, or a range consisting of any two of these.

[0085] In a preferred embodiment, the aqueous solution in step S2 contains an additive, which is an acid receiver. The acid receiver is selected from a weak base, a buffer pair composed of a weak base and an acid, or any one or a mixture of alkali metal hydroxides, carbonates and bicarbonates, and organic acid salts (such as salts containing sulfonic acids or carboxylic acids, or a mixture thereof). Preferably, the weak base is selected from any one or a mixture of triethylamine and sodium phosphate; the buffer pair composed of the weak base and the acid is selected from any one or a mixture of triethylamine hydrochloride and triethylamine camphor sulfonate; the alkali metal hydroxides, carbonates and bicarbonates are selected from any one or a mixture of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate; the organic compound is selected from any one or a mixture of tetramethylammonium hydroxide and tetraethylammonium hydroxide; more preferably, the acid receiver is triethylamine camphor sulfonate.

[0086] In the aqueous solution, the concentration of the additive is 1.0 to 20.0 wt%, including but not limited to 1.0 wt%, 3.0 wt%, 5.0 wt%, 7.0 wt%, 9.0 wt%, 10.0 wt%, 12.0 wt%, 14.0 wt%, 16.0 wt%, 18.0 wt%, 10.0 wt%, or any combination thereof, and the pH of the aqueous solution is controlled to be 9.0 to 12.0, including but not limited to 9.0, 9.5, 10.0, 10.5, 11.0, 11.5, 12.0, or any combination thereof. Preferably, the aqueous solution contains 1.1–3.5 wt% triethylamine and 2.3–6.5 wt% camphor sulfonic acid, which form a buffer for triethylamine camphor sulfonate. Specifically, the concentration of triethylamine can be 1.1 wt%, 1.3 wt%, 1.5 wt%, 1.7 wt%, 2.0 wt%, 2.3 wt%, 2.5 wt%, 2.8 wt%, 3.0 wt%, 3.2 wt%, 3.5 wt%, or any two of these concentrations. The concentration of camphor sulfonic acid can be 2.3 wt%, 2.5 wt%, 2.8 wt%, 3.0 wt%, 3.3 wt%, 3.5 wt%, 3.8 wt%, 4.0 wt%, 4.3 wt%, 4.5 wt%, 4.8 wt%, 5.0 wt%, 5.3 wt%, 5.5 wt%, 5.8 wt%, 6.0 wt%, 6.3 wt%, 6.5 wt%, or any combination thereof.

[0087] In a preferred embodiment, the polysulfone ultrafiltration support layer described in step S2 is in contact with the aqueous solution and remains there for a period of time, which is 10 to 120 seconds, preferably 30 to 60 seconds; the residence temperature can be room temperature, for example, 10 to 50°C, preferably 15 to 35°C; specifically, the residence time can be 10 seconds, 20 seconds, 30 seconds, 40 seconds, 50 seconds, 60 seconds, 70 seconds, 80 seconds, 90 seconds, 100 seconds, 110 seconds, 120 seconds or any combination thereof, and the residence temperature can be 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C or any combination thereof.

[0088] In a preferred embodiment, the polyacryl chloride in step S3 is selected from aromatic and / or aliphatic polyacryl chlorides; preferably, the aromatic polyacryl chloride includes, but is not limited to, any one or a mixture of several of pyromellitic tricarboxylic acid chloride, terephthaloyl chloride, isophthaloyl chloride, and naphthiadicarboxylic acid chloride, and the aliphatic polyacryl chloride includes, but is not limited to, any one or a mixture of several of malonyl chloride, succinyl chloride, adipyl chloride, and 1,4-cyclohexanediol chloride; more preferably, the polyacryl chloride is pyromellitic tricarboxylic acid chloride;

[0089] In the organic phase solution, the concentration of polyacrylamide chloride is 0.01 to 1.0 wt%, including but not limited to 0.01 wt%, 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1.0 wt%, or any combination thereof, preferably 0.05 to 0.5 wt%.

[0090] In a preferred embodiment, the solvent in the organic phase solution described in step S3 is selected from any one or a mixture of several of n-hexane, cyclohexane, n-heptane, n-decane, isoalkanes Isopar G, and isoalkanes Isopar L, preferably any one or a mixture of several of n-hexane, cyclohexane, and isoalkanes Isopar G.

[0091] In a preferred embodiment, step S3 involves contacting the polysulfone ultrafiltration support layer with the organic phase solution to perform an interfacial polymerization reaction. The reaction is carried out at a temperature of 10–50°C, preferably 15–35°C, for a time of 10–60 seconds, preferably 30–60 seconds. Specifically, the temperature can be 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, or any combination thereof, and the time can be 10 seconds, 15 seconds, 20 seconds, 25 seconds, 30 seconds, 35 seconds, 40 seconds, 45 seconds, 50 seconds, 55 seconds, 60 seconds, or any combination thereof.

[0092] In a preferred embodiment, the heat treatment in step S3 is performed at a temperature of 50–120°C, preferably 60–100°C, for a time of 3–10 minutes, preferably 3–5 minutes. Specifically, the temperature can be 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, or any combination thereof, and the time can be 3 minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes, or any combination thereof.

[0093] The hydrophilic polymer antifouling layer of the present invention is a polymer formed by crosslinking a diblock hydrophilic polymer containing pyrrolidone segments and amino segments with a small molecule compound containing epoxy groups and / or allyl groups.

[0094] In a preferred embodiment, the diblock hydrophilic polymer comprising pyrrolidone and amino segments described in step S4 has a weight-average molecular weight ranging from 20,000 to 150,000 Da, preferably from 40,000 to 80,000 Da; its weight-average molecular weight and molecular weight distribution (PDI) range from 1 to 5, preferably from 1 to 3; and its actual pyrrolidone / amino molar ratio ranges from 2 to 20, preferably from 3 to 10. Specifically, the weight-average molecular weight can be 20,000 Da, 30,000 Da, 40,000 Da, 50,000 Da, 60,000 Da, or 70,000 Da. The PDI value can be 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5 or any two of these values, and the actual pyrrolidone / amino molar ratio can be 2, 4, 6, 8, 10, 12, 14, 16, 18, 20 or any two of these values.

[0095] In a preferred embodiment, the diblock hydrophilic polymer comprising pyrrolidone segments and amino segments in step S4 is a diblock copolymer synthesized by free radical copolymerization. The synthesized monomer comprises two parts, one part being a hydrophilic pyrrolidone and the other part being an amino group capable of chemically reacting with the membrane surface groups.

[0096] In a preferred embodiment, the diblock hydrophilic polymer comprising pyrrolidone segments and amino segments is a diblock copolymer synthesized by free radical copolymerization, wherein the monomers include pyrrolidone-containing monomers and amino-containing monomers.

[0097] Preferably, the pyrrolidone-containing monomer includes, but is not limited to, any one or a mixture of several of vinylpyrrolidone, 3-allylpyrrolidone-2-one, 3-(2-methylprop-2-enyl)pyrrolidone-2-one, 3-(3-buten-1-yl)-2-pyrrolidone, 3-(3-buten-1-yl)-3-(2-propen-1-yl)-2-pyrrolidone, and 1-(1-propenyl)pyrrolidone-2-one, more preferably vinylpyrrolidone;

[0098] Preferably, the amino-containing monomer includes, but is not limited to, any one or a mixture of several of N-methylallylamine, diallylamine, allylethylamine, 2-methylpropenamine, N-ethylmethylpropenamine, and allylamine, and more preferably, any one or a mixture of several of N-methylallylamine and diallylamine.

[0099] In actual operation, the pyrrolidone-containing monomer and the amino-containing monomer can be fed in any positive ratio. Preferably, the mass ratio of the pyrrolidone-containing monomer and the amino-containing monomer is 95:5 to 75:25, including but not limited to 95:5, 90:10, 85:15, 80:20, 75:25 or any range thereof.

[0100] The free radical copolymerization method described above involves reacting to synthesize diblock copolymers in the presence of an initiator. The initiator is selected from any one or a mixture of several of azobisisobutyronitrile, azobisisoheptanenitrile, and benzoyl peroxide, preferably azobisisobutyronitrile.

[0101] The initiator dosage is 0.01 to 5.0% of the total mass of the pyrrolidone monomer and the amino monomer, including but not limited to 0.01 wt%, 0.1 wt%, 1.0 wt%, 1.5 wt%, 2.0 wt%, 2.5 wt%, 3.0 wt%, 3.5 wt%, 4.0 wt%, 4.5 wt%, 1.0 wt%, or any combination thereof, preferably 0.5 to 2.0%.

[0102] The free radical copolymerization method involves reacting and synthesizing diblock copolymers in a solvent environment. The solvent is selected from any one or a mixture of several of N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, tetrahydrofuran, ethylene glycol methyl ether, diethylene glycol dimethyl ether, ethyl acetate, dioxane, and pyridine, preferably N-methylpyrrolidone.

[0103] The solvent content accounts for 20-99% of the total mass of the reaction system, including but not limited to 20wt%, 30wt%, 40wt%, 50wt%, 60wt%, 70wt%, 80wt%, 90wt%, 99wt%, or any combination thereof, preferably 40-80%.

[0104] The free radical copolymerization method described above is a known process in the prior art. The relevant operations and process conditions in the preparation method of this invention, as well as the apparatus used, can all be carried out using conventional methods in the art, and there are no particular restrictions. Those skilled in the art can optimize the process based on existing known processes according to actual needs, for example:

[0105] The free radical copolymerization method described herein has a reaction temperature of 50–100°C, preferably 70–90°C, and a reaction time of 0.5–24 hours, preferably 4–8 hours. Specifically, the reaction temperature can be 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, or any combination thereof, and the reaction time can be 0.5 hours, 1 hour, 3 hours, 5 hours, 8 hours, 10 hours, 12 hours, 15 hours, 18 hours, 20 hours, 22 hours, 24 hours, or any combination thereof.

[0106] In a preferred embodiment, the concentration of the diblock hydrophilic polymer comprising pyrrolidone segments and amino segments in the aqueous solution described in step S4 is 0.01 to 10.0 wt%, including but not limited to 0.01 wt%, 0.1 wt%, 1.0 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, or any combination thereof, preferably 0.05 to 1.0 wt%.

[0107] In some embodiments, the aqueous solution described in step S4 contains a surfactant selected from sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, hexadecyl ammonium bromide, dodecyl trimethyl ammonium bromide, dodecyl dimethyl benzyl ammonium bromide, tetrabutyl ammonium bromide, cocoyl glucoside, lauryl glucoside, sucrose esters, polysorbates (Tween), polyoxyethylene derivatives, polyoxyethylene-polyoxypropylene copolymers, and polyvinylpyrrolidone, preferably selected from sodium dodecyl sulfate, polyvinylpyrrolidone, and Tween 80;

[0108] In the aqueous solution, the concentration of the surfactant is 0.01 to 10.0 wt%, including but not limited to 0.01 wt%, 0.1 wt%, 1.0 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, or any combination thereof, preferably 0.10 to 1.0 wt%.

[0109] In some embodiments, the grafting reaction in step S4 is carried out at a temperature of 10–60°C, preferably 20–40°C, and for a reaction time of 10–600 seconds, preferably 30–180 seconds. Specifically, the reaction temperature can be 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, or any combination thereof, and the reaction time can be 10 seconds, 50 seconds, 100 seconds, 150 seconds, 200 seconds, 250 seconds, 300 seconds, 350 seconds, 400 seconds, 450 seconds, 500 seconds, 550 seconds, 600 seconds, or any combination thereof.

[0110] In a preferred embodiment, the small molecule compound containing epoxy and / or allyl groups in step S5 includes, but is not limited to, any one or a mixture of several of polyethylene glycol diglycidyl ether, ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, bisphenol A diglycidyl ether, trimethylolpropane triglycidyl ether, allyl glycidyl ether, and active allyl epoxy polyether, preferably any one or a mixture of several of polyethylene glycol diglycidyl ether, allyl glycidyl ether, and active allyl epoxy polyether;

[0111] In the aqueous solution, the concentration of the small molecule compound containing epoxy and / or allyl groups is 0.01 to 2.0 wt%, including but not limited to 0.01 wt%, 0.1 wt%, 0.3 wt%, 0.5 wt%, 0.8 wt%, 1.0 wt%, 1.2 wt%, 1.4 wt%, 1.6 wt%, 1.8 wt%, 2.0 wt%, or any combination thereof, preferably 0.05 to 0.5 wt%.

[0112] In a preferred embodiment, the thermal crosslinking reaction in step S5 is carried out at a temperature of 50–100°C, preferably 60–90°C, and for a reaction time of 30–600 seconds, preferably 60–300 seconds. Specifically, the reaction temperature can be 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, or any combination thereof, and the reaction time can be 30 seconds, 50 seconds, 100 seconds, 150 seconds, 200 seconds, 250 seconds, 300 seconds, 350 seconds, 400 seconds, 450 seconds, 500 seconds, 550 seconds, 600 seconds, or any combination thereof.

[0113] Specifically, a method for preparing a high-organic-removal, fouling-resistant polyamide reverse osmosis membrane according to the present invention includes the following steps:

[0114] S1: The degassed polysulfone casting solution is coated onto polyethylene terephthalate nonwoven fabric, and then the polysulfone ultrafiltration support layer is obtained by phase conversion in a gel bath.

[0115] S2: Immerse the polysulfone ultrafiltration support layer in an aqueous solution containing polyamine monomers and additives for 10 to 120 seconds, then remove it and remove the residual aqueous solution from the surface.

[0116] S3: Pour the prepared organic phase solution containing polyacrylamide chloride onto the surface of the polysulfone ultrafiltration support layer for interfacial polymerization reaction. After reacting for 10 to 60 seconds, pour off the organic phase solution and place it in an oven for heat treatment. Then, use compressed air or nitrogen air knife to blow away the membrane surface to remove excess organic phase solution. Finally, rinse the membrane surface with pure water until it becomes hydrophilic to form the nascent polyamide layer.

[0117] S4: Rinse the membrane surface with an aqueous solution containing a hydrophilic polymer and a surfactant, leave it for 10 to 600 seconds, rinse with pure water, and then graft the hydrophilic polymer.

[0118] S5: After rinsing with pure water, the membrane is placed in an aqueous solution of a small molecule compound containing epoxy or allyl groups for thermal crosslinking for 30 to 600 seconds to obtain the antifouling polyamide reverse osmosis membrane with high organic matter removal.

[0119] The main raw materials used in the following examples or comparative examples are listed in Table 1 below. Unless otherwise specified, other raw materials and reagents were obtained through commercially available channels.

[0120] Table 1. Information on the Sources of Main Raw Materials

[0121]

[0122]

[0123]

[0124] The analytical methods used or potentially used in the embodiments or comparative examples of this invention are described below:

[0125] 1. Evaluation of desalination rate and permeability

[0126] Desalination rate and permeate flux are two important parameters for evaluating the separation performance of reverse osmosis membranes. This invention evaluates the separation performance of reverse osmosis membranes according to GB / T32373-2015 "Test Methods for Reverse Osmosis Membranes".

[0127] Desalination rate (R) is defined as: under certain operating conditions, the salt concentration (C) of the feed solution... f ) and the salt concentration in the permeate (C p The difference between the two is then divided by the feed solution salt concentration (C). f ), as in formula (1).

[0128]

[0129] Permeation flux is defined as the volume of water that permeates through a unit membrane area per unit time under certain operating conditions, and its unit is L·m. -2 ·h -1 .

[0130] The operating conditions used for the reverse osmosis membrane performance determination in this invention are as follows: the feed solution is a 2000ppm sodium chloride aqueous solution, the solution pH is 7.0±0.5, the operating pressure is 225psi (1.55MPa), and the operating temperature is 25±1℃.

[0131] 2. Evaluation of organic matter removal rate

[0132] Organic matter removal rate (R) is defined as: under certain operating conditions, the organic matter concentration (C) of the feed liquid. f ) and the concentration of organic matter in the permeate (C p The difference between the two is then divided by the feed solution salt concentration (C). f ), as in formula (1).

[0133] The operating conditions used for measuring the reverse osmosis membrane performance in this invention are as follows: the feed solution is an aqueous solution of 2000 ppm sodium chloride and 100 ppm isopropanol, the solution pH is 7.0 ± 0.5, the operating pressure is 225 psi (1.55 MPa), and the operating temperature is 25 ± 1℃. The concentration of isopropanol was determined using a total organic carbon analyzer (Shanghai Yuanxi TOC-5000).

[0134] 3. Dynamic anti-pollution performance evaluation

[0135] The permeation flux decay rate (FDR) is defined as the rate of decay of the membrane's test permeation flux (F2) compared to the initial permeation flux (F1) after a period of operation following the addition of contaminants to the test system. It is 1-F2 / F1.

[0136] Flux recovery rate (FRR) is defined as the ratio of the tested flux (F3) of the membrane after fouling and acid / alkali cleaning to the initial flux (F1) before fouling, which is F3 / F1.

[0137] The dynamic antifouling test conditions for the reverse osmosis membrane in this invention are as follows:

[0138] F1 is the flux obtained after the membrane is subjected to cross-flow filtration of an aqueous solution at 25°C, pH 7.0±0.5, and sodium chloride concentration of 2000ppm for 1 hour under a pressure of 1.55MPa.

[0139] F2 is the flux obtained after adding bovine serum albumin and polyoxyethylene 20 oil ether (both pollutants) to the sodium chloride aqueous solution above, with the concentration of both at 100 ppm, and continuing to run for 2 hours after measuring F1.

[0140] F3 represents the flux obtained after washing the membrane with a NaOH solution at pH 12.0 ± 0.5 for 12 hours, following measurements of F1 and F2, and after cross-flow filtration of an aqueous solution at 25°C, pH 7.0 ± 0.5, and a sodium chloride concentration of 2000 ppm for 1 hour under a pressure of 1.55 MPa.

[0141] 4. Membrane water contact angle test

[0142] The water contact angle was measured using a Krüss DSA (water contact angle meter). The reverse osmosis membranes were dried in a vacuum oven at 80°C for one day. The test method involved dropping 1–4 μL of deionized water onto the membrane surface and calculating the water contact angle 10 seconds after the pure water droplet landed. Five measurements were taken at appropriate test locations, and the average value was calculated.

[0143] 5. Molecular weight test of hydrophilic polymers

[0144] Before testing, the hydrophilic polymer was precipitated from the post-polymerization mixture using diethylene glycol dimethyl ether. The precipitate was then washed three times with diethyl ether, filtered, and vacuum dried to obtain the hydrophilic polymer.

[0145] Permeation gel chromatography (Shimadzu CTO-20A) was used for testing. The chromatographic column was Shim-pack GPC-80M, the guard column was Shim-pack GPC 800p, the mobile phase was tetrahydrofuran, the flow rate was set to 1.0 mL / min, the column temperature was set to 50℃, the injection volume was set to 50 μL, and the detector was a differential refractive index detector RID-10A. Four polyvinylpyrrolidone (PVP) of different molecular weights (PVP K16-18, K23-27, K29-32 and K88-96) were selected as standards. A standard curve was plotted, and the weight-average molecular weight and molecular weight distribution (PDI, the ratio of weight-average molecular weight to number-average molecular weight) of the hydrophilic polymers were determined.

[0146] 6. Test of the actual pyrrolidone / amino molar ratio in hydrophilic polymers

[0147] Before testing, the hydrophilic polymer was precipitated from the post-polymerization mixture using diethylene glycol dimethyl ether. The precipitate was then washed three times with diethyl ether, filtered, and vacuum dried to obtain the hydrophilic polymer.

[0148] 2 mg of the hydrophilic polymer was dissolved in 2 mL of deuterated chloroform, then placed in a nuclear magnetic resonance (HMR) sample tube, and its proton NMR spectrum was measured using a Bruker AVANCE NEO 400M NMR spectrometer. 1 H NMR was performed at a temperature of 20–25 °C for a total of 32 measurements. The spectral results were analyzed using MestReNova software. The peaks at 2.7–4.0 ppm were determined to originate from hydrogen atoms on either side of the carbon atom in vinylpyrrolidone (3H) and N-methylallylamine (5H) or diallylamine (4H). The peak at 2.2 ppm originated from hydrogen atoms on the carbonyl adjacent carbon atom in vinylpyrrolidone (2H). The baselines of each peak were determined using the software, and the peak areas were integrated. The area of ​​the hydrogen peak on either side of the carbon atom in vinylpyrrolidone was A. C-N The area of ​​the hydrogen peak on the carbonyl adjacent carbon atom is A. C＝O The calculated actual pyrrolidone / amino molar ratio is 5A. C＝O / (2A C-N -3A C＝O (The amino monomer is N-methylallylamine) or 4A C＝O / (2A C-N -3A C＝O (The amino monomer is diallylamine). Preparation of a diblock hydrophilic polymer containing pyrrolidone and amino segments:

[0149] Example 1 of the synthesis of diblock hydrophilic polymers

[0150] Vinylpyrrolidone monomer and N-methylallylamine monomer were synthesized by free radical reaction at a mass ratio of 90:10, with a solid content of 40% by mass. The solvent was N-methylpyrrolidone, the reaction temperature was 78℃, the initiator was azobisisobutyronitrile (AIBN) at 0.5% of the total monomer mass, and the reaction time was 4 hours. The resulting diblock hydrophilic polymer 1 had a final polymer weight-average molecular weight of 61,000, a PDI of 1.91, and an actual pyrrolidone / amino ratio of 7.4.

[0151] Example 2 of the synthesis of diblock hydrophilic polymers

[0152] Unlike Example 1, which synthesizes diblock hydrophilic polymers, vinylpyrrolidone and N-methylallylamine are synthesized by free radicals at a mass ratio of 80:20 to obtain diblock hydrophilic polymer 2. The final polymer has a weight-average molecular weight of 53,000, a PDI of 2.14, and an actual pyrrolidone / amino ratio of 3.4.

[0153] Example 3 of the synthesis of diblock hydrophilic polymers

[0154] Unlike Example 1, which synthesizes diblock hydrophilic polymers, vinylpyrrolidone and N-methylallylamine are synthesized by free radicals at a mass ratio of 95:5 to obtain diblock hydrophilic polymer 3. The final polymer has a weight-average molecular weight of 65,000, a PDI of 2.26, and an actual pyrrolidone / amino ratio of 13.3.

[0155] Example 4 of the synthesis of diblock hydrophilic polymers

[0156] Unlike Example 1, which synthesizes diblock hydrophilic polymers, vinylpyrrolidone and diallylamine are synthesized by free radicals at a mass ratio of 90:10 to obtain diblock hydrophilic polymer 4. The final polymer has a weight-average molecular weight of 59,000, a PDI of 2.05, and an actual pyrrolidone / amino ratio of 8.5.

[0157] Example 5 of the synthesis of diblock hydrophilic polymers

[0158] The difference from Example 1, which synthesized a diblock hydrophilic polymer, is that the reaction temperature was 90°C, the initiator was benzoyl peroxide at a rate of 0.5% of the total monomer mass, and the reaction time was 4 hours, resulting in diblock hydrophilic polymer 5. The final polymer had a weight-average molecular weight of 57,000, a PDI of 2.13, and an actual pyrrolidone / amino ratio of 7.2.

[0159] Comparative Synthesis Example 1 of Hydrophilic Polymers

[0160] Vinylpyrrolidone was synthesized by free radical method with a solid content of 40% by mass, N-methylpyrrolidone as the solvent, 78°C as the reaction temperature, azobisisobutyronitrile as the initiator at 0.5% of the total monomer mass, and 4 hours as the reaction time, to obtain hydrophilic polymer 1. The final polymer had a weight-average molecular weight of 70,000 and a PDI of 1.82.

[0161] Example 1

[0162] The preparation process of a fouling-resistant polyamide reverse osmosis membrane with high organic matter removal capability is as follows:

[0163] Step 1: Prepare a polysulfone ultrafiltration support layer on the surface of polyethylene terephthalate nonwoven fabric. Specifically, prepare a polysulfone casting solution containing 16.5 wt% polysulfone resin in N,N-dimethylformamide; then coat the filtered and degassed polysulfone casting solution onto the polyethylene terephthalate nonwoven fabric; immediately immerse it in deionized water in a coagulation bath to form a membrane through phase inversion, and then wash it with water to obtain the polysulfone ultrafiltration support layer, which is then cut into 16cm×12cm membrane sheets.

[0164] Step 2: Dissolve m-phenylenediamine, camphor sulfonic acid, and triethylamine in deionized water, stir and mix evenly to prepare an aqueous solution containing 2.5 wt% m-phenylenediamine, 3.2 wt% camphor sulfonic acid, and 1.6 wt% triethylamine. Camphor sulfonic acid and triethylamine form a buffer, p-triethylamine camphor sulfonate. The pH of the aqueous solution is about 11.5.

[0165] Step 3: Dissolve pyromellitic chloride in isopar G isoalkane, stir and mix evenly to prepare an organic phase solution containing 0.12 wt% pyromellitic chloride;

[0166] Step 4: Attach the polysulfone ultrafiltration support membrane prepared in Step 1, surface-up, to the plate frame. Immerse it in the aqueous solution prepared in Step 2 at 25°C for 60 seconds. Then remove the plate frame and place it on a paper towel on top of the plastic plate. Gently squeeze with a pressure roller to remove excess aqueous solution remaining on the surface. Then, contact it with the organic solution containing trimesoyl chloride from Step 3 and perform an interfacial polymerization reaction at 25°C for 30 seconds. Discard the excess organic solution. Then, use an air knife to evenly blow away the solvent until there is no residual solvent on the membrane surface. Finally, place it in an 80°C oven for heat treatment for 5 minutes. After removing it from the oven, rinse the membrane surface with pure water until it becomes hydrophilic.

[0167] Step 5: Contact the membrane surface obtained in Step 4 with an aqueous solution of 0.1 wt% diblock hydrophilic polymer 1 and 0.5 wt% sodium dodecyl sulfate, and perform a grafting reaction at 25°C for 30 seconds. After discarding the excess solution, wash the membrane surface with pure water.

[0168] Step Six: Place the membrane obtained in Step Five into an aqueous solution of 0.1 wt% active allyl epoxy polyether KL-11B and perform a thermal crosslinking reaction at 80°C for 180 seconds. Finally, remove the membrane and rinse it with pure water to obtain the antifouling polyamide reverse osmosis membrane with high organic matter removal in Example 1.

[0169] Example 2

[0170] The difference from Example 1 is that in step five, an aqueous solution of 0.01 wt% diblock hydrophilic polymer 1 and 0.1 wt% sodium dodecyl sulfate is used, and the grafting reaction is carried out at 25°C for 90 seconds. All other operations and conditions remain unchanged, resulting in the antifouling polyamide reverse osmosis membrane with high organic matter removal capacity as described in Example 2.

[0171] Example 3

[0172] The difference from Example 1 is that in step five, an aqueous solution of 10.0 wt% diblock hydrophilic polymer 1 and 10.0 wt% sodium dodecyl sulfate is used, and the grafting reaction is carried out at 25°C for 10 seconds. All other operations and conditions remain unchanged, resulting in the antifouling polyamide reverse osmosis membrane with high organic matter removal capacity as described in Example 3.

[0173] Example 4

[0174] The difference from Example 1 is that in step five, an aqueous solution of 0.1 wt% diblock hydrophilic polymer 2 and 0.5 wt% polyvinylpyrrolidone K29-32 is used instead. All other operations and conditions remain unchanged, resulting in the antifouling polyamide reverse osmosis membrane with high organic matter removal capacity as described in Example 4.

[0175] Example 5

[0176] The difference from Example 1 is that in step five, an aqueous solution of 0.1 wt% diblock hydrophilic polymer 3 and 0.5 wt% Tween 80 is used instead, while other operations and conditions remain unchanged, resulting in the antifouling polyamide reverse osmosis membrane with high organic matter removal capacity of Example 5.

[0177] Example 6

[0178] The difference from Example 1 is that in step five, an aqueous solution of 0.1 wt% diblock hydrophilic polymer 4 and 0.5 wt% decyl glucoside is used instead, while other operations and conditions remain unchanged, resulting in the antifouling polyamide reverse osmosis membrane with high organic matter removal capacity as described in Example 6.

[0179] Example 7

[0180] The difference from Example 1 is that in step five, an aqueous solution of 0.01 wt% diblock hydrophilic polymer 5 and 0.5 wt% sodium dodecyl sulfate is used instead. All other operations and conditions remain unchanged, resulting in the antifouling polyamide reverse osmosis membrane with high organic matter removal capacity as described in Example 7.

[0181] Example 8

[0182] The difference from Example 1 is that in step five, an aqueous solution of 0.1 wt% diblock hydrophilic polymer 1 and 10.0 wt% dodecyl dimethyl benzyl ammonium bromide is used, the solution temperature is 60°C, and the grafting reaction is carried out for 10 seconds. In step six, an aqueous solution of 0.1 wt% allyl glycidyl ether is used. All other operations and conditions remain unchanged, resulting in the antifouling polyamide reverse osmosis membrane with high organic matter removal capacity as described in Example 8.

[0183] Example 9

[0184] The difference from Example 1 is that in step five, an aqueous solution of 0.1 wt% diblock hydrophilic polymer 1 and 0.01 wt% cocoyl glucoside is used, the solution temperature is 10°C, and the grafting time is 600 seconds. In step six, an aqueous solution of 0.1 wt% polyethylene glycol diglycidyl ether is used. All other operations and conditions remain unchanged, resulting in the antifouling polyamide reverse osmosis membrane with high organic matter removal capacity as described in Example 10.

[0185] Example 10

[0186] The difference from Example 1 is that in step six, an aqueous solution of 2.0 wt% ethylene glycol diglycidyl ether at 100°C is used, and the thermal crosslinking reaction is carried out for 30 seconds. All other operations and conditions remain unchanged, resulting in the antifouling polyamide reverse osmosis membrane with high organic matter removal capacity as described in Example 11.

[0187] Example 11

[0188] The difference from Example 1 is that in step six, an aqueous solution of 0.01wt% 1,4-butanediol diglycidyl ether at 50°C is used, and the thermal crosslinking reaction is carried out for 600 seconds. All other operations and conditions remain unchanged, resulting in the antifouling polyamide reverse osmosis membrane with high organic matter removal capacity as described in Example 12.

[0189] Comparative Example 1

[0190] The difference from Example 1 is that the grafting reaction in step five and the thermal crosslinking reaction in step six are omitted, while all other operations and conditions remain unchanged.

[0191] The membrane prepared in step four was taken out and rinsed with pure water until it became hydrophilic, thus obtaining the reverse osmosis membrane of Comparative Example 1.

[0192] Comparative Example 2

[0193] The difference from Example 1 is that the thermal crosslinking reaction in step six is ​​omitted, while other operations and conditions remain unchanged. The membrane prepared in step five is washed with pure water to obtain the reverse osmosis membrane of Comparative Example 2.

[0194] Comparative Example 3

[0195] The difference from Example 1 is that the grafting reaction in step five is omitted. The membrane prepared in step four is taken out, rinsed with pure water until it becomes hydrophilic, and directly used for the thermal crosslinking reaction in step six. All other operations and conditions remain unchanged, resulting in the reverse osmosis membrane of Comparative Example 3.

[0196] Comparative Example 4

[0197] The difference from Example 1 is that in step five, the hydrophilic polymer 1 with a concentration of 10.0 wt% and sodium dodecyl sulfate solution with a concentration of 0.5 wt% are replaced. All other operations and conditions remain unchanged, resulting in a high organic matter removal capacity and antifouling polyamide reverse osmosis membrane as described in Comparative Example 4.

[0198] Comparative Example 5

[0199] The difference from Example 1 is that, according to the method of patent CN 113634130 A, step five is replaced with a methanol aqueous solution of 2.0 wt% polyvinylpyrrolidone K29-32 and 0.01 wt% α-ketoglutaric acid (methanol to water volume ratio of 1:1), the solution temperature is 25°C, the contact time is 20 seconds, and then the membrane obtained in step five is placed under a UV lamp with a wavelength of 236 nm, with the membrane surface 5 cm away from the UV lamp, and irradiated for 10 seconds to obtain the antifouling polyamide reverse osmosis membrane of Comparative Example 5.

[0200] The performance indicators and test data of the reverse osmosis membranes prepared in the embodiments and comparative examples of the present invention are listed in Table 2.

[0201] Table 2. Performance data of the antifouling layer of the reverse osmosis membrane.

[0202]

[0203]

[0204] As can be seen from the experimental results in Table 2, compared with Comparative Example 1 (which lacks a hydrophilic polymer antifouling layer), the membrane in Example 2 exhibits better hydrophilicity and superior antifouling performance, while maintaining essentially the same initial separation performance and showing improved isopropanol removal rate, indicating promising application prospects. Comparative Example 2, compared to Comparative Example 1, also shows better hydrophilicity, antifouling performance, and isopropanol removal performance, demonstrating that single-grafted diblock hydrophilic polymers can also improve membrane antifouling and organic matter removal rates. Comparative Example 3, compared to Comparative Example 1, demonstrates superior isopropanol removal performance, indicating that using only active allyl epoxy polyether can enhance the membrane's organic matter removal performance.

[0205] The above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A high-organic-removal, fouling-resistant polyamide reverse osmosis membrane, characterized in that, It includes a polyester nonwoven fabric layer, a polysulfone ultrafiltration support layer, a polyamide separation bottom membrane layer, and a hydrophilic polymer antifouling layer; The polyamide separation bottom membrane layer is a cross-linked polymer formed by the interfacial polycondensation reaction of polyamines and polyacryl chlorides; The hydrophilic polymer antifouling layer is a polymer formed by cross-linking a diblock hydrophilic polymer containing pyrrolidone segments and amino segments with a small molecule compound containing epoxy groups and / or allyl groups. The diblock hydrophilic polymer comprising pyrrolidone and amino segments has a weight-average molecular weight range of 20,000 to 150,000 Da, a weight-average molecular weight and molecular weight distribution (PDI) range of 1 to 5, and an actual pyrrolidone / amino molar ratio of 2 to 20.

2. The antifouling polyamide reverse osmosis membrane with high organic matter removal capability according to claim 1, characterized in that, The polyester nonwoven layer is made of a material selected from any one or a mixture of several of polyethylene terephthalate, polypropylene terephthalate, and polybutylene terephthalate; and / or The polysulfone ultrafiltration support layer is a porous ultrafiltration membrane formed by coating a polyester nonwoven fabric layer with polysulfone material, with a pore size of 1~100nm and a thickness of 20~150μm.

3. The antifouling polyamide reverse osmosis membrane with high organic matter removal according to claim 2, characterized in that, The porous ultrafiltration membrane has a pore size of 1~50nm and a thickness of 30~80μm.

4. The antifouling polyamide reverse osmosis membrane with high organic matter removal according to claim 1, characterized in that, The polyamine is an aromatic amine or an aliphatic amine containing at least two primary amino groups; and / or The polyacyl chloride is selected from aromatic and / or aliphatic polyacyl chlorides.

5. The antifouling polyamide reverse osmosis membrane with high organic matter removal according to claim 4, characterized in that, The aromatic amine is selected from any one or a mixture of several of phenylenediamine or phenylenediamine, 1,3,5-triaminobenzene, which are bonded to the benzene ring at the ortho, meta, and para positions. The aliphatic amine is selected from any one or a mixture of several of ethylenediamine, propylenediamine, and piperazine.

6. The antifouling polyamide reverse osmosis membrane with high organic matter removal according to claim 4, characterized in that, The aromatic polyacryl chloride is selected from any one or a mixture of several of pyromellitic tricarboxylic acid chloride, terephthaloyl chloride, isophthaloyl chloride, and naphthiadicarboxylic acid chloride, and the aliphatic polyacryl chloride is selected from any one or a mixture of several of malonyl chloride, succinyl chloride, adipicoyl chloride, and 1,4-cyclohexadicarboxylic acid chloride.

7. The antifouling polyamide reverse osmosis membrane with high organic matter removal according to claim 4, characterized in that, The polyamine is m-phenylenediamine; the polyacrylamide is pyromellitic chloride.

8. The antifouling polyamide reverse osmosis membrane with high organic matter removal according to claim 1, characterized in that, The diblock hydrophilic polymer comprising pyrrolidone and amino segments has a weight-average molecular weight range of 40,000–80,000 Da; a weight-average molecular weight and molecular weight distribution (PDI) range of 1–3; and an actual pyrrolidone / amino molar ratio of 3–10; and / or The diblock hydrophilic polymer comprising pyrrolidone and amino segments is a diblock copolymer synthesized by free radical copolymerization, wherein the monomers include pyrrolidone-containing monomers and amino-containing monomers; and / or The small molecule compound containing epoxy and / or allyl groups is selected from any one or a mixture of several of polyethylene glycol diglycidyl ether, ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, bisphenol A diglycidyl ether, trimethylolpropane triglycidyl ether, allyl glycidyl ether, and active allyl epoxy polyether.

9. The antifouling polyamide reverse osmosis membrane with high organic matter removal according to claim 8, characterized in that, The pyrrolidone-containing monomer is selected from any one or a mixture of several of vinylpyrrolidone, 3-allylpyrrolidone-2-one, 3-(2-methylprop-2-enyl)pyrrolidone-2-one, 3-(3-buten-1-yl)-2-pyrrolidone, 3-(3-buten-1-yl)-3-(2-propen-1-yl)-2-pyrrolidone, and 1-(1-propenyl)pyrrolidone-2-one.

10. The antifouling polyamide reverse osmosis membrane with high organic matter removal according to claim 8, characterized in that, The amino-containing monomer is selected from any one or a mixture of several of N-methylallylamine, diallylamine, allylethylamine, 2-methylpropenamine, N-ethylmethylpropenamine, and allylamine.

11. The antifouling polyamide reverse osmosis membrane with high organic matter removal according to claim 8, characterized in that, The mass ratio of the pyrrolidone-containing monomer to the amino-containing monomer is 95:5 to 75:

25.

12. The antifouling polyamide reverse osmosis membrane with high organic matter removal according to claim 8, characterized in that, A diblock copolymer is synthesized by reaction in the presence of an initiator selected from one or a mixture of several of azobisisobutyronitrile, azobisisoheptanenitrile, and benzoyl peroxide.

13. The antifouling polyamide reverse osmosis membrane with high organic matter removal according to claim 12, characterized in that, The amount of initiator used is 0.01 to 5.0% of the total mass of the pyrrolidone monomer and the amino monomer.

14. The antifouling polyamide reverse osmosis membrane with high organic matter removal according to claim 13, characterized in that, The amount of initiator used is 0.5 to 2.0% of the total mass of the pyrrolidone monomer and the amino monomer.

15. The antifouling polyamide reverse osmosis membrane with high organic matter removal according to claim 8, characterized in that, The reaction is carried out in a solvent environment to synthesize the diblock copolymer, wherein the solvent is selected from any one or a mixture of several of N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, tetrahydrofuran, ethylene glycol methyl ether, diethylene glycol dimethyl ether, ethyl acetate, dioxane, and pyridine.

16. The antifouling polyamide reverse osmosis membrane with high organic matter removal according to claim 15, characterized in that, The amount of solvent used accounts for 20-99% of the total mass of the reaction system.

17. The antifouling polyamide reverse osmosis membrane with high organic matter removal according to claim 16, characterized in that, The amount of solvent used accounts for 40-80% of the total mass of the reaction system.

18. The antifouling polyamide reverse osmosis membrane with high organic matter removal according to claim 8, characterized in that, The free radical copolymerization method described herein has a reaction temperature of 50~100℃ and a reaction time of 0.5~24 hours.

19. The antifouling polyamide reverse osmosis membrane with high organic matter removal according to claim 18, characterized in that, The free radical copolymerization method described herein involves a reaction temperature of 70-90°C and a reaction time of 4-8 hours.

20. A method for preparing a high-organic-removal, fouling-resistant polyamide reverse osmosis membrane as described in any one of claims 1-19, characterized in that, The method includes the following steps: S1: Obtain a polysulfone ultrafiltration support layer on the surface of a polyester nonwoven fabric layer; S2: Immerse the polysulfone ultrafiltration support layer in an aqueous solution containing polyamines and additives, leave it for a period of time, and then remove the residual aqueous solution from the surface. S3: The surface of the polysulfone ultrafiltration support layer is brought into contact with an organic phase solution containing polyacrylamide chloride for interfacial polymerization reaction. After reacting for a period of time, the residual organic phase solution on the surface is removed, followed by heat treatment, and then water washing until the membrane surface is hydrophilic to form a polyamide separation bottom membrane layer. S4: The surface of the polyamide separation substrate layer is brought into contact with an aqueous solution containing a diblock hydrophilic polymer containing pyrrolidone segments and amino segments and a surfactant to carry out a grafting reaction. After reacting for a period of time, the residual aqueous solution on the surface is removed, and then the surface is rinsed with water to obtain a polyamide separation substrate layer grafted with hydrophilic polymer. S5: The surface of the polyamide separation bottom membrane layer grafted with hydrophilic polymer is brought into contact with an aqueous solution containing small molecule compounds including epoxy groups and / or allyl groups for thermal crosslinking reaction. After reacting for a period of time, the residual aqueous solution on the surface is removed, and then the membrane is rinsed with water to obtain the antifouling polyamide reverse osmosis membrane with high organic matter removal.

21. The preparation method according to claim 20, characterized in that, In the aqueous solution described in step S2, the concentration of the polyamine is 0.5~10.0 wt%; and / or In the aqueous solution described in step S2, the concentration of the additive is 1.0~20.0 wt%; and / or The additive mentioned in step S2 is an acid acceptor, which is selected from a weak base, a buffer pair composed of a weak base and an acid, or any one or a mixture of several of alkali metal hydroxides, carbonates and bicarbonates, and organic acid salts; and / or The dwell time mentioned in step S2 is 10 to 120 seconds.

22. The preparation method according to claim 21, characterized in that, In the aqueous solution, the concentration of polyamine is 1.0~5.0 wt%.

23. The preparation method according to claim 21, characterized in that, The pH of the aqueous solution is 9.0~12.

0.

24. The preparation method according to claim 21, characterized in that, The weak base is selected from any one or a mixture of several of triethylamine and sodium phosphate; the buffer pair formed by the weak base and acid is selected from any one or a mixture of several of triethylamine hydrochloride and triethylamine camphor sulfonate; the alkali metal hydroxide, carbonate and bicarbonate are selected from any one or a mixture of several of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate and potassium bicarbonate.

25. The preparation method according to claim 21, characterized in that, The aqueous solution contains 1.1-3.5 wt% triethylamine and 2.3-6.5 wt% camphor sulfonic acid.

26. The preparation method according to claim 20, characterized in that, In the organic phase solution described in step S3, the concentration of polyacrylamide chloride is 0.01~1.0 wt%; and / or In the organic phase solution described in step S3, the solvent is selected from any one or a mixture of several of the following: n-hexane, cyclohexane, n-heptane, n-decane, isoalkanes Isopar G, and isoalkanes Isopar L; and / or The interfacial polymerization reaction described in step S3 is carried out at a temperature of 10~50℃ for a time of 10~60 seconds; and / or The heat treatment described in step S3 is performed at a temperature of 50~120℃ for 3~10 minutes.

27. The preparation method according to claim 26, characterized in that, In the organic phase solution, the concentration of polyacryl chloride is 0.05~0.5wt%.

28. The preparation method according to claim 26, characterized in that, The solvent is selected from any one or a mixture of several of n-hexane, cyclohexane, and isoparaffin IsoparG.

29. The preparation method according to claim 26, characterized in that, The interfacial polymerization reaction is carried out at a temperature of 15~35℃ for 30~60 seconds.

30. The preparation method according to claim 26, characterized in that, The heat treatment is performed at a temperature of 60-100℃ for 3-5 minutes.

31. The preparation method according to claim 20, characterized in that, In the aqueous solution described in step S4, the concentration of the diblock hydrophilic polymer containing pyrrolidone segments and amino segments is 0.01~10.0 wt%; and / or In the aqueous solution described in step S4, the concentration of the surfactant is 0.01~10.0 wt%; and / or The surfactant described in step S4 is selected from any one or a mixture of several of the following: sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, hexadecyl ammonium bromide, dodecyltrimethylammonium bromide, dodecyl dimethyl benzyl ammonium bromide, tetrabutylammonium bromide, cocoyl glucoside, lauryl glucoside, sucrose esters, polysorbates (Tween), polyoxyethylene derivatives, polyoxyethylene-polyoxypropylene copolymers, and polyvinylpyrrolidone; and / or The grafting reaction described in step S4 is carried out at a temperature of 10~60℃ and for a time of 10~600 seconds.

32. The preparation method according to claim 31, characterized in that, In the aqueous solution, the concentration of the diblock hydrophilic polymer containing pyrrolidone segments and amino segments is 0.05~1.0wt%.

33. The preparation method according to claim 31, characterized in that, In the aqueous solution, the concentration of the surfactant is 0.10~1.0wt%.

34. The preparation method according to claim 31, characterized in that, The grafting reaction is carried out at a temperature of 20-40°C for 30-180 seconds.

35. The preparation method according to claim 20, characterized in that, In the aqueous solution described in step S5, the concentration of small molecule compounds containing epoxy groups and / or allyl groups is 0.01~2.0 wt%; and / or The thermal crosslinking reaction described in step S5 has a reaction temperature of 50~100℃ and a reaction time of 30~600 seconds.

36. The preparation method according to claim 35, characterized in that, The concentration of small molecule compounds containing epoxy groups and / or allyl groups in the aqueous solution is 0.05~0.5wt%.

37. The preparation method according to claim 35, characterized in that, The thermal crosslinking reaction is carried out at a temperature of 60-90°C for 60-300 seconds.

38. Use of a high organic matter removal antifouling polyamide reverse osmosis membrane, wherein the reverse osmosis membrane is prepared by any one of claims 1-19 or by any one of claims 20-37, and the reverse osmosis membrane is used in a water treatment assembly or water treatment method.

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