Anti-pollution polyamide reverse osmosis membrane with high organic matter removal rate as well as preparation method and application of anti-pollution polyamide reverse osmosis membrane

Abstract

The invention discloses a high organic matter removal anti-pollution polyamide reverse osmosis membrane and a preparation method and application thereof, the polyamide reverse osmosis membrane sequentially comprises a polyester non-woven fabric layer, a polysulfone ultrafiltration support layer, a polyamide separation bottom membrane layer and a hydrophilic polymer anti-pollution layer; the polyamide separation bottom membrane layer is a cross-linked polymer formed by an interfacial polycondensation reaction of polyamine and polyacyl chloride; the hydrophilic polymer anti-pollution layer is a polymer formed by carrying out a cross-linking reaction on a diblock hydrophilic polymer containing a pyrrolidone chain segment and an amino chain segment and a small molecular compound containing an epoxy group and / or an allyl group. The polyamide reverse osmosis membrane has good application prospects in the fields of removal of organic matters in pure water in the electronic industry, removal of trace organic matters in domestic drinking water and the like.

Description

Technical Field

[0001] The invention relates to the technical field of reverse osmosis, and in particular to an anti-pollution polyamide reverse osmosis membrane with high organic matter removal, a preparation method and application thereof. Background Art

[0002] At present, polyamide reverse osmosis membrane technology, as an efficient, affordable and mainstream separation technology, has been widely used in the fields of seawater desalination, brackish water desalination, industrial wastewater treatment, municipal sewage treatment, household water purification and industrial pure water manufacturing. At present, the pure water prepared in the electronics industry needs to use polyamide reverse osmosis membrane to remove some small molecular organic matter contained therein. According to the current production process and process involved in the electronics industry, it can be confirmed that the organic matter present in pure water includes alcohols, aldehydes, carboxylic acids and some amino-containing organic small molecules. During the use of the reverse osmosis membrane, due to the deposition and adsorption of these organic matter and the chemical interaction with the membrane surface during mechanical, physical or filtration processes, membrane contamination occurs on the surface of the reverse osmosis membrane, resulting in a decrease in the water production of the reverse osmosis membrane. Because the reverse osmosis membrane in the electronics industry cannot be regularly cleaned with acid and alkali like the reverse osmosis membrane in the sewage treatment or seawater desalination industry to remove the residual pollutants on the membrane surface and restore the water production of the membrane. Therefore, it is very important to develop an anti-pollution reverse osmosis membrane with small flux attenuation during operation and high acid and alkali cleaning recovery rate. It is of great significance to reduce the frequency of acid and alkali cleaning, improve the recovery rate of membrane water production after cleaning, and extend the service life of the reverse osmosis membrane.

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

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

[0005] Compared with traditional hydrophilic polymers (such as polyvinyl alcohol and polyethylene glycol), polyvinyl pyrrolidone is a hydrophilic polymer with more stable chemical properties and better biocompatibility. When polyvinyl pyrrolidone is modified on the coating surface, the hydrophilic pyrrolidone units in the chain can bind water molecules to form a hydration layer, effectively eliminating the electrostatic and hydrophobic interactions between biomacromolecules and the material surface, and forming a stable anti-biological adhesion interface.

[0006] Since there are no reaction sites in the molecular structure of polyvinyl pyrrolidone that react with the groups (amino, amide and carboxyl) on the polyamide layer, it is difficult for polyvinyl pyrrolidone to be connected to the membrane surface through chemical bonds. Currently, polyvinyl pyrrolidone mainly acts on the polyamide layer in three ways. The first way is to directly physically coat it on the surface of the polyamide layer. For example, Chinese invention patent CN201480043520 discloses a method for preparing an anti-pollution reverse osmosis membrane by directly coating a polyvinyl pyrrolidone solution and then drying it in an oven. Since polyvinyl pyrrolidone only has hydrogen bonds with the membrane surface, it is easy to fall off during actual operation. The second method is to construct an intermediate layer on the surface of the polyamide layer and then apply polyvinyl pyrrolidone. For example, Chinese invention patent CN201510166251 discloses a method of using tannic acid and ferric chloride to form a complex intermediate layer on the surface of the polyamide layer, and then introducing polyvinyl pyrrolidone to the surface of the reverse osmosis membrane. The prepared anti-pollution membrane has good anti-pollution performance against pollutants such as proteins and polysaccharides. Although there is a strong hydrogen bond between the complex and polyvinyl pyrrolidone, there is still a problem of polyvinyl pyrrolidone layer falling off after multiple acid and alkali cleanings in actual operation. The third method is to add vinyl pyrrolidone monomer to the aqueous phase and photoinitiate polymerization to form a polyvinyl pyrrolidone anti-pollution layer or use a photoinitiator ultraviolet irradiation method to graft polyvinyl pyrrolidone to the surface of the polyamide layer. For example, Chinese invention patent CN201910016832 discloses a method of adding vinyl pyrrolidone to an aqueous solution, interfacial polymerization, and then irradiating with gamma rays to obtain an anti-pollution reverse osmosis membrane with relatively excellent anti-pollution performance. Although this method forms a chemical bond connection, the gamma-ray irradiation treatment is dangerous and time-consuming, and it is difficult to apply it to the actual production process. Chinese invention patent CN202010392827 discloses a method for fixing polyvinyl pyrrolidone on the surface of a polyamide membrane by polymerizing polyvinyl pyrrolidone with the carbon-carbon double bonds in the polyamide layer under the action of the photoinitiator benzophenone through ultraviolet irradiation. The prepared reverse osmosis membrane has improved anti-pollution performance and desalination rate. Vinyl pyrrolidone is added to an aqueous solution, and after interfacial polymerization, it is irradiated with gamma rays to obtain an anti-pollution reverse osmosis membrane with relatively excellent anti-pollution performance. Although this method can be carried out more conveniently in the actual production process, since the solvent used is a mixed solution of water and methanol in a mass ratio of 1:1, the risk in production is still relatively large.

[0007] Therefore, there is a need in the art to develop a method for efficiently and conveniently connecting polyvinyl pyrrolidone to the surface of a reverse osmosis membrane with a strong chemical bond to form an anti-fouling layer. Summary of the invention

[0008] In order to solve the problems existing in the prior art, the present invention provides a high organic matter removal anti-pollution polyamide reverse osmosis membrane which is simple to prepare and suitable for industrial continuous production and a preparation method, so as to improve the anti-pollution performance and cleaning recovery performance of the existing reverse osmosis membrane, and at the same time improve the removal of trace organic matter in water by the membrane.

[0009] In order to achieve the above invention object, the present invention adopts the following technical solutions:

[0010] In a first aspect, the present invention provides a high organic matter removal anti-pollution polyamide reverse osmosis membrane, which comprises a polyester non-woven fabric layer, a polysulfone ultrafiltration support layer, a polyamide separation bottom membrane layer, and a hydrophilic polymer anti-pollution layer in sequence;

[0011] The polyamide separation bottom membrane layer is a cross-linked polymer formed by interfacial polycondensation reaction of polyamine and polyacyl chloride;

[0012] The hydrophilic polymer anti-pollution layer is a polymer formed by cross-linking reaction between a diblock hydrophilic polymer containing a pyrrolidone chain segment and an amino chain segment and a small molecule compound containing an epoxy group and / or an allyl group.

[0013] In one embodiment, after the polyamide separation base membrane layer is constructed in situ on the membrane surface of the polysulfone ultrafiltration support layer, a diblock hydrophilic polymer containing a pyrrolidone segment and an amino segment is first grafted onto the polyamide separation base membrane, and then cross-linked with a small molecule compound containing an epoxy group and / or an allyl group to form the hydrophilic polymer anti-fouling layer.

[0014] In the study of polyamide reverse osmosis membranes, the inventors of the present application unexpectedly discovered that by grafting a hydrophilic polymer onto the primary polyamide layer and then cross-linking it with a small molecule compound containing an epoxy or allyl group, the initial performance of the membrane, such as flux and salt rejection rate, did not decrease significantly, and the membrane had more stable and long-lasting anti-pollution performance. At the same time, the removal rate of the membrane for trace organic matter in water (such as alcohols, amines, ketones, organic acids and other organic matter) was significantly improved.

[0015] The possible mechanism of action of the technical solution of the present invention is analyzed as follows: First, the hydrophilic polymer reacts with the residual acyl chloride on the primary polyamide layer through the amino group in its molecule, and is connected to the surface of the polyamide layer through the formed amide bond. Since the hydrophilic polymer has a large molecular weight and a certain flexibility, a part of the hydrophilic polymer chain segment will be embedded in the polyamide layer to cross-link 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 an anti-pollution layer with a cross-linked structure. Since the anti-pollution layer contains a large number of hydrophilic groups, it can avoid the situation where the flux is greatly reduced as caused by other anti-pollution coating polymers. More importantly, the anti-pollution layer is chemically bonded, and the anti-pollution layer is a cross-linked structure that is not easy to fall off. After multiple acid and alkali cleanings, it can still maintain a high anti-pollution performance, and at the same time, the removal rate of trace organic matter (alcohols, amines, ketones, organic acids and other organic matter) in water is significantly improved.

[0016] In some embodiments, the polyester nonwoven fabric layer includes, but is not limited to, any one or a mixture of polyethylene terephthalate, polypropylene terephthalate, and polybutylene terephthalate;

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

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

[0019] In some embodiments, the polyamine 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 phenylenediamine or phenylenediamine, 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 ethylenediamine, propylenediamine, and piperazine;

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

[0021] In some embodiments, the polyacyl chloride is selected from aromatic and / or aliphatic polyacyl chlorides; preferably, the aromatic polyacyl chloride includes but is not limited to any one or a mixture of trimesoyl chloride, terephthaloyl chloride, isophthaloyl chloride, and naphthalene dicarboxylic acid chloride, and the aliphatic polyacyl chloride includes but is not limited to any one or a mixture of malonyl chloride, succinyl chloride, adipoyl chloride, and 1,4-cyclohexanedicarboxylic acid chloride;

[0022] More preferably, the polyacid chloride is trimesoyl chloride.

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

[0024] In some embodiments, the diblock hydrophilic polymer comprising a pyrrolidone segment and an amino segment is a diblock copolymer synthesized by a free radical copolymerization method, and the synthetic monomers include a pyrrolidone-containing monomer and an amine-containing monomer;

[0025] Preferably, the pyrrolidone-containing monomer includes but is not limited to any one or a mixture of vinyl pyrrolidone, 3-allyl pyrrolidone-2-one, 3-(2-methylprop-2-enyl) pyrrolidone-2-one, 3-(3-butene-1-yl)-2-pyrrolidone, 3-(3-butene-1-yl)-3-(2-propene-1-yl)-2-pyrrolidone, 1-(1-propenyl) pyrrolidone-2-one, more preferably vinyl pyrrolidone;

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

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

[0028] The above-mentioned free radical copolymerization method is to react in the presence of an initiator to synthesize a diblock copolymer, wherein the initiator is selected from any one of azobisisobutyronitrile, azobisisoheptanenitrile, and benzoyl peroxide, or a mixture of several of them, preferably azobisisobutyronitrile;

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

[0030] The above-mentioned free radical copolymerization method is to react and synthesize the diblock copolymer in a solvent environment, wherein the solvent is selected from any one 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, or a mixture thereof, preferably N-methylpyrrolidone;

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

[0032] The above-mentioned free radical copolymerization method is a known process in the prior art. The relevant operations and process conditions in the preparation method of the present invention, and the devices used therein, can be carried out by using the corresponding conventional selections in the art, and there is no particular limitation thereto. The technicians can optimize the known processes in the prior art according to actual needs, for example:

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

[0034] In some embodiments, the small molecule compound containing epoxy and / or allyl groups includes but is not limited to any one 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, or a mixture of several of them, preferably any one of polyethylene glycol diglycidyl ether, allyl glycidyl ether, and active allyl epoxy polyether, or a mixture of several of them.

[0035] In a second aspect, the present invention provides a method for preparing the above-mentioned anti-pollution polyamide reverse osmosis membrane with high organic matter removal, which can be prepared by combined screening based on conventional processes in the art according to the structure actually required to be formed.

[0036] Specifically, a method for preparing a high organic matter removal anti-pollution polyamide reverse osmosis membrane comprises the following steps:

[0037] S1: obtaining a polysulfone ultrafiltration support layer on the surface of the polyester non-woven fabric layer;

[0038] S2: immersing the polysulfone ultrafiltration support layer in an aqueous solution containing polyamine and additives for a period of time, and removing the aqueous solution remaining on the surface after taking it out;

[0039] S3: contacting the surface of the polysulfone ultrafiltration support layer with an organic phase solution containing polyacid chlorides to perform interfacial polymerization reaction, reacting for a period of time, removing the organic phase solution remaining on the surface, and then performing heat treatment, and then washing with water until the membrane surface is hydrophilic (i.e., there is no droplet agglomeration on the membrane surface), to form a polyamide separation bottom membrane layer;

[0040] S4: contacting the surface of the polyamide separation bottom membrane layer with an aqueous solution containing a diblock hydrophilic polymer including a pyrrolidone segment and an amino segment and a surfactant to carry out a grafting reaction, reacting for a period of time, removing the aqueous solution remaining on the surface, and then washing with water to obtain a polyamide separation bottom membrane layer grafted with the hydrophilic polymer;

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

[0042] For the preparation method of the present invention, the raw material selection listed above can be referred to. For other related operations and process conditions, and the devices used therein, corresponding conventional selections in the art can be adopted. There is no particular limitation to this. The technicians can optimize the known processes in the prior art according to actual needs. Specifically, for example, the conditions listed in the following embodiments of the present invention can be adopted:

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

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

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

[0046] In a specific embodiment, the aqueous phase solution contains an additive, the additive is an acid acceptor, and the acid acceptor is selected from a weak base, or a buffer pair consisting of a weak base and an acid, or any one or a mixture of alkali metal hydroxides, carbonates and bicarbonates, organic acids (such as sulfonic acids, carboxylic acids, one or a mixture of several salts), etc.;

[0047] Preferably, the weak base is selected from any one of triethylamine and sodium phosphate or a mixture of several thereof; the buffer pair composed of the weak base and the acid is selected from any one of triethylamine hydrochloride and triethylamine camphorsulfonate or a mixture of several thereof; the hydroxide, carbonate and bicarbonate of the alkali metal is selected from any one of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate and potassium bicarbonate or a mixture of several thereof; the organic compound is selected from any one of tetramethylammonium hydroxide and tetraethylammonium hydroxide or a mixture of several thereof;

[0048] More preferably, the acid acceptor is triethylamine camphorsulfonate.

[0049] In a preferred embodiment, the aqueous phase solution contains 1.1-3.5 wt % of triethylamine and 2.3-6.5 wt % of camphorsulfonic acid.

[0050] In some embodiments, the dwelling period in step S2 is 10 to 120 seconds.

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

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

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

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

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

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

[0057] In some embodiments, the aqueous solution described in step S4 contains a surfactant, and the surfactant is selected from any one or a mixture of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, hexadecyl ammonium bromide, dodecyltrimethylammonium bromide, dodecyldimethylbenzylammonium bromide, tetrabutylammonium bromide, coconut glucoside, lauryl glucoside, sucrose esters, polysorbate (Tween), polyoxyethylenes, polyoxyethylene-polyoxypropylene copolymers, and polyvinyl pyrrolidone, preferably any one or a mixture of sodium dodecyl sulfate, polyvinyl pyrrolidone and Tween 80.

[0058] In some embodiments, the grafting reaction in step S4 has a reaction temperature of 10 to 60° C., preferably 20 to 40° C., and a reaction time of 10 to 600 seconds, preferably 30 to 180 seconds.

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

[0060] In some embodiments, the thermal crosslinking reaction in step S5 has a reaction temperature of 50 to 100° C., preferably 60 to 90° C., and a reaction time of 30 to 600 seconds, preferably 60 to 300 seconds.

[0061] In a third aspect, the present invention also provides the use of the above-mentioned anti-pollution polyamide reverse osmosis membrane with high organic matter removal.

[0062] The anti-pollution polyamide reverse osmosis membrane with high organic matter removal of the present invention has the advantages of low flux loss, high desalination rate, anti-pollution and the like. Specifically, the flux loss is less than 20%, the desalination rate can be as high as 99.3% or more, and the removal rate of trace organic matter (such as isopropanol) in water can be higher than 90%. A use of an anti-pollution polyamide reverse osmosis membrane with high organic matter removal, the reverse osmosis membrane is prepared by the above method, or is the above reverse osmosis membrane, and the reverse osmosis membrane is used in a water treatment component or a water treatment method.

[0063] The water treatment component can be any component or device installed with the reverse osmosis membrane of the present invention that can be used in the water treatment process, including those used to prepare such components or devices; the component can be, for example, a spiral membrane component and a disc-tube flat membrane component, or a household / commercial reverse osmosis water purifier, an industrial boiler feed water reverse osmosis pure water device, an industrial reclaimed water 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 in pure water and drinking water, etc.

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

[0065] 1) The present invention provides an anti-pollution polyamide reverse osmosis membrane with high organic matter removal, which has low flux loss and high desalination rate, while taking into account stable and long-term anti-pollution performance.

[0066] 2) The hydrophilic anti-pollution layer of the polyamide reverse osmosis membrane of the present invention is a chemically cross-linked structure, which is chemically bonded to the polyamide layer, and its structure is more stable. After multiple acid and alkali cleanings, it can still maintain a high anti-pollution performance. At the same time, the chemical cross-linking further cross-links the polyamide inside and the polyamide and the anti-pollution layer, thereby improving the removal rate of trace organic matter in water.

[0067] 3) The hydrophilic polymer in the polyamide reverse osmosis membrane of the present invention is free radical copolymerized, without subsequent separation and purification process, simple operation and low production cost. At the same time, the hydrophilic polymer anti-pollution layer grafting process does not need to modify the current process, and is easy to industrialize and produce. DETAILED DESCRIPTION

[0068] In order to better understand the technical solution of the present invention, the following examples will further illustrate the method provided by the present invention, but the present invention is not limited to the listed examples, and should also include any other known changes within the scope of the claims of the present invention.

[0069] A high organic matter removal anti-pollution polyamide reverse osmosis membrane, which comprises in sequence a polyester non-woven 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 anti-pollution layer.

[0070] The anti-pollution polyamide reverse osmosis membrane with high organic matter removal of the present invention, the polysulfone ultrafiltration support layer is a polysulfone ultrafiltration membrane layer formed on the surface of the polyester non-woven fabric layer. The preparation of the polysulfone ultrafiltration support layer can adopt the existing well-known technology in the field, and no limitation is made to this.

[0071] In a preferred embodiment, the pore size of the polysulfone ultrafiltration support layer is in the range of 1 to 100 nm, preferably 1 to 50 nm; its thickness is in the range of 20 to 150 μm, preferably 30 to 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 a range consisting of any two thereof; the thickness can be 20 μm, 40 μm, 60 μm, 80 μm, 100 μm, 120 μm, 140 μm, 150 μm, or a range consisting of any two thereof;

[0072] In a preferred embodiment, the polymer solution for preparing the polysulfone ultrafiltration support layer may contain 15.0-20.0wt% of polysulfone resin, and these components are dissolved in a polar solvent to obtain a polysulfone casting solution. Specifically, the concentration of the polysulfone resin in the polymer solution may be 15.0wt%, 15.4wt%, 16.0wt%, 16.5wt%, 17.0wt%, 17.5wt%, 18.0wt%, 18.5wt%, 19.0wt%, 19.5wt%, 20.0wt% or a range consisting of any two thereof; then the filtered and degassed polysulfone casting solution is scraped onto the surface of a polyester non-woven fabric (such as a polyethylene terephthalate non-woven fabric, etc.); then the solution enters a gel bath to undergo phase transformation to form a membrane, and after washing, a 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 bottom membrane layer in situ constructed on the polysulfone ultrafiltration support layer of the present invention can be prepared by the known technology in the art, and is not particularly limited to this. In a preferred specific embodiment, the polyamide separation bottom 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 (such as m-phenylenediamine) and polyacyl chlorides (such as trimesoyl chloride).

[0074] The hydrophilic polymer anti-pollution layer of the present invention is prepared by a step-by-step grafting method, wherein a diblock hydrophilic polymer containing a pyrrolidone segment and an amino segment is first grafted, and then cross-linked by a small molecule compound containing an epoxy group and / or an allyl group to form a hydrophilic polymer anti-pollution layer. After washing with water, an anti-pollution polyamide reverse osmosis membrane with high organic matter removal is obtained.

[0075] A method for preparing a high organic matter removal anti-pollution polyamide reverse osmosis membrane comprises the following steps:

[0076] S1: coating a polysulfone material on the surface of a polyester non-woven fabric layer, and obtaining a polysulfone ultrafiltration support layer through phase inversion;

[0077] S2: immersing the polysulfone ultrafiltration support layer in an aqueous solution containing polyamine and additives for a period of time, and removing the aqueous solution remaining on the surface after taking it out;

[0078] S3: contacting the surface of the polysulfone ultrafiltration support layer with an organic phase solution containing polyacid chloride to perform interfacial polymerization reaction, reacting for a period of time, removing the organic phase solution remaining on the surface, and then performing heat treatment, and then washing with water until the membrane surface is hydrophilic (no droplet agglomeration), to form a polyamide separation bottom membrane layer;

[0079] S4: contacting the surface of the polyamide separation bottom membrane layer with an aqueous solution containing a diblock hydrophilic polymer including a pyrrolidone segment and an amino segment and a surfactant to carry out a grafting reaction, reacting for a period of time, removing the aqueous solution remaining on the surface, and then washing with water to obtain a polyamide separation bottom membrane layer grafted with the hydrophilic polymer;

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

[0081] In the preparation method of the present invention, step S1 of obtaining a base membrane layer having a surface covered with a polysulfone ultrafiltration support layer can be prepared by referring to the method listed above, and other raw material selections, related operations and process conditions, and the devices used can all be carried out using the corresponding conventional selections in the art, without any particular restrictions. Technicians can optimize the known processes based on the prior art according to actual needs, and the present invention will not go into details here.

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

[0083] In a preferred embodiment, the polyamine described 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 phenylenediamine or phenylenediamine, 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 ethylenediamine, propylenediamine, and piperazine; more preferably, the polyfunctional amine is metaphenylenediamine;

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

[0085] In a preferred embodiment, the aqueous phase solution described in step S2 contains an additive, and the additive is an acid acceptor, and the acid acceptor is selected from a weak base, or a buffer pair composed of a weak base and an acid, or any one or a mixture of alkali metal hydroxides, carbonates and bicarbonates, organic acids (such as one or a mixture of sulfonic acids and carboxylic acids), etc.; 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 camphorsulfonate; the alkali metal hydroxide, carbonate and bicarbonate are selected from any one or a mixture of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate; the organic compound is selected from any one or a mixture of tetramethylammonium hydroxide and tetraethylammonium hydroxide; more preferably, the acid acceptor is triethylamine camphorsulfonate;

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

[0087] In a preferred specific embodiment, the polysulfone ultrafiltration support layer described in step S2 contacts with the aqueous phase solution and stays for a period of time, the residence time 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 a range consisting of any two 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 a range consisting of any two thereof.

[0088] In a preferred embodiment, the polyacyl chloride in step S3 is selected from aromatic and / or aliphatic polyacyl chlorides; preferably, the aromatic polyacyl chloride includes but is not limited to any one or a mixture of trimesoyl chloride, terephthaloyl chloride, isophthaloyl chloride, and naphthalene dicarboxylic acid chloride, and the aliphatic polyacyl chloride includes but is not limited to any one or a mixture of malonyl chloride, succinyl chloride, adipoyl chloride, and 1,4-cyclohexanedicarboxylic acid chloride; more preferably, the polyacyl chloride is trimesoyl chloride;

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

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

[0091] In a preferred specific embodiment, step S3 contacts the polysulfone ultrafiltration support layer with the organic phase solution for interfacial polymerization reaction, and the reaction temperature is 10-50°C, preferably 15-35°C, and the time is 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 a range consisting of any two 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 a range consisting of any two thereof.

[0092] In a preferred specific embodiment, the heat treatment in step S3 is performed at a temperature of 50 to 120°C, preferably 60 to 100°C, and for a time of 3 to 10 minutes, preferably 3 to 5 minutes; specifically, the temperature may be 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C or a range consisting of any two thereof, and the time may be 3 minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes or a range consisting of any two thereof.

[0093] The hydrophilic polymer anti-pollution layer of the present invention is a polymer formed by cross-linking reaction between a diblock hydrophilic polymer containing a pyrrolidone chain segment and an amino chain segment and a small molecule compound containing an epoxy group and / or an allyl group.

[0094] In a preferred embodiment, the diblock hydrophilic polymer comprising a pyrrolidone segment and an amino segment in step S4 has a weight average molecular weight in the range of 20,000 to 150,000 Da, preferably 40,000 to 80,000 Da; a weight average molecular weight and a molecular weight distribution value (PDI) in the range of 1 to 5, preferably 1 to 3; an actual pyrrolidone / amino molar ratio in the range of 2 to 20, preferably 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, 70,000 Da, 80,000 Da, 90,000 Da, 100,000 Da, 110,000 Da, 120,000 Da, 130,000 Da, 140,000 Da, 150,000 Da, 160,000 Da, 170,000 Da, 180,000 Da, 190,000 Da, 200,000 Da, 210,000 Da, 230,000 Da, 240,000 Da, 250,000 Da, 260,000 Da, 270,000 Da, 280,000 Da, 290,000 Da, 300,000 Da, 310,000 Da, 310,000 Da, 320,000 Da, 330,000 Da, 340,000 Da, 350,000 Da, 360,000 Da, 370,000 Da, 380,000 Da, 000Da, 80000Da, 90000Da, 100000Da, 110000Da, 120000Da, 130000Da, 140000Da, 150000Da or a range consisting of any two thereof, the PDI value may be 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5 or a range consisting of any two thereof, and the actual pyrrolidone / amino molar ratio may be 2, 4, 6, 8, 10, 12, 14, 16, 18, 20 or a range consisting of any two thereof.

[0095] In a preferred embodiment, the diblock hydrophilic polymer comprising a pyrrolidone segment and an amino segment in step S4 is a diblock copolymer synthesized by a free radical copolymerization method, and the synthesized monomer comprises two parts, one of which is a hydrophilic pyrrolidone and the other is an amino group that can chemically react with the membrane surface group.

[0096] In a preferred embodiment, the diblock hydrophilic polymer comprising a pyrrolidone segment and an amino segment is a diblock copolymer synthesized by a free radical copolymerization method, and the synthetic monomers include a pyrrolidone-containing monomer and an amine-containing monomer;

[0097] Preferably, the pyrrolidone-containing monomer includes but is not limited to any one or a mixture of vinyl pyrrolidone, 3-allyl pyrrolidone-2-one, 3-(2-methylprop-2-enyl) pyrrolidone-2-one, 3-(3-butene-1-yl)-2-pyrrolidone, 3-(3-butene-1-yl)-3-(2-propene-1-yl)-2-pyrrolidone, 1-(1-propenyl) pyrrolidone-2-one, more preferably vinyl pyrrolidone;

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

[0099] In the actual operation process, the pyrrolidone-containing monomer and the amino-containing monomer can be fed in any positive proportion. Preferably, the feeding 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 a range consisting of any two thereof.

[0100] The above-mentioned free radical copolymerization method is to react in the presence of an initiator to synthesize a diblock copolymer, wherein the initiator is selected from any one of azobisisobutyronitrile, azobisisoheptanenitrile, and benzoyl peroxide, or a mixture of several of them, preferably azobisisobutyronitrile;

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

[0102] The free radical copolymerization method comprises reacting in a solvent environment to synthesize a diblock copolymer, wherein the solvent is selected from any one 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, or a mixture thereof, preferably N-methylpyrrolidone;

[0103] The amount of the solvent is 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 a range consisting of any two thereof, preferably 40-80%.

[0104] The above-mentioned free radical copolymerization method is a known process in the prior art. The relevant operations and process conditions in the preparation method of the present invention, and the devices used therein, can be carried out by using the corresponding conventional selections in the art, and there is no particular limitation thereto. The technicians can optimize the known processes in the prior art according to actual needs, for example:

[0105] The method for free radical copolymerization has a reaction temperature of 50 to 100° C., preferably 70 to 90° C., and a reaction time of 0.5 to 24 hours, preferably 4 to 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 a range consisting of any two thereof, and the reaction time can be 0.5 hour, 1 hour, 3 hours, 5 hours, 8 hours, 10 hours, 12 hours, 15 hours, 18 hours, 20 hours, 22 hours, 24 hours or a range consisting of any two thereof.

[0106] In a preferred embodiment, in the aqueous solution described in step S4, the concentration of the diblock hydrophilic polymer comprising a pyrrolidone segment and an amino segment 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 a range consisting of any two thereof, preferably 0.05 to 1.0 wt%;

[0107] In some embodiments, the aqueous solution described in step S4 contains a surfactant, and the surfactant is selected from any one or a mixture of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, hexadecyl ammonium bromide, dodecyltrimethylammonium bromide, dodecyldimethylbenzylammonium bromide, tetrabutylammonium bromide, coconut glucoside, lauryl glucoside, sucrose ester, polysorbate (Tween), polyoxyethylene, polyoxyethylene-polyoxypropylene copolymer, polyvinyl pyrrolidone, preferably any one or a mixture of sodium dodecyl sulfate, polyvinyl pyrrolidone 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 a range consisting of any two thereof, preferably 0.10 to 1.0 wt%.

[0109] In some embodiments, the grafting reaction described in step S4 has a reaction temperature of 10 to 60°C, preferably 20 to 40°C, and a reaction time of 10 to 600 seconds, preferably 30 to 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 a range consisting of any two 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 a range consisting of any two 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 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 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 0.01-2.0wt%, including but not limited to 0.01wt%, 0.1wt%, 0.3wt%, 0.5wt%, 0.8wt%, 1.0wt%, 1.2wt%, 1.4wt%, 1.6wt%, 1.8wt%, 2.0wt% or a range consisting of any two thereof, preferably 0.05-0.5wt%.

[0112] In a preferred specific embodiment, the thermal cross-linking reaction in step S5 has a reaction temperature of 50 to 100°C, preferably 60 to 90°C, and a reaction time of 30 to 600 seconds, preferably 60 to 300 seconds; specifically, the reaction temperature may be 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C or a range consisting of any two thereof, and the reaction time may 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 a range consisting of any two thereof.

[0113] Specifically, a method for preparing a high organic matter removal anti-pollution polyamide reverse osmosis membrane of the present invention comprises the following steps:

[0114] S1: The degassed polysulfone casting solution is applied on a polyethylene terephthalate non-woven fabric, and then phase-converted by a gel bath to obtain a polysulfone ultrafiltration support layer;

[0115] S2: immersing the polysulfone ultrafiltration support layer in an aqueous solution containing a polyamine monomer and an additive for 10 to 120 seconds, then taking it out and removing the aqueous solution remaining on the surface;

[0116] S3: pouring the prepared organic phase solution containing polyacyl chloride onto the surface of the polysulfone ultrafiltration support layer for interfacial polymerization reaction for 10 to 60 seconds, pouring out the organic phase solution, placing it in an oven for heat treatment, then using compressed air or nitrogen air knife to blow the membrane surface to remove excess organic phase solution, and then using pure water to rinse the membrane surface until it is hydrophilic to form a primary polyamide layer;

[0117] S4: The membrane surface is rinsed with an aqueous solution containing a hydrophilic polymer and a surfactant, and after leaving for 10 to 600 seconds, it is rinsed with pure water, and then the hydrophilic polymer is grafted.

[0118] S5: placing the membrane rinsed with pure water into an aqueous solution of a small molecule compound containing epoxy or allyl groups for thermal crosslinking for 30 to 600 seconds to obtain the anti-pollution polyamide reverse osmosis membrane with high organic matter removal.

[0119] The sources of the main raw materials used in the following examples or comparative examples are shown in Table 1. Other raw materials and reagents were purchased from commercial sources unless otherwise specified:

[0120] Table 1 Main raw material sources information

[0121]

[0122]

[0123]

[0124] The following describes the analytical methods used or may be used in the embodiments or comparative examples of the present invention:

[0125] 1. Evaluation of desalination rate and permeation flux

[0126] Salt rejection rate and permeation flux are two important parameters for evaluating the separation performance of reverse osmosis membranes. The present invention evaluates the separation performance of reverse osmosis membranes according to GB / T32373-2015 "Test Method for Reverse Osmosis Membrane".

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

[0128]

[0129] Permeation flux is defined as the volume of water that passes 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 in the reverse osmosis membrane performance measurement in the present invention are: the feed liquid is a 2000 ppm sodium chloride aqueous solution, the solution pH is 7.0±0.5, the operating pressure is 225 psi (1.55 MPa), and the operating temperature is 25±1°C.

[0131] 2. Evaluation of organic matter removal rate

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

[0133] The operating conditions used in the reverse osmosis membrane performance measurement in the present invention are: the feed liquid is 2000 ppm of sodium chloride and 100 ppm of isopropanol aqueous solution, the solution pH is 7.0±0.5, the operating pressure is 225 psi (1.55 MPa), and the operating temperature is 25±1° C. The concentration of isopropanol is measured 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: after the pollutants are added to the test system and the system has been running for a period of time, the decay rate of the test permeation flux (F2) of the membrane compared to the initial permeation flux (F1) is 1-F2 / F1.

[0136] The permeation flux recovery rate (FRR) is defined as: after contamination, the membrane is cleaned with acid and alkali, the ratio of the test flux (F3) of the membrane to the initial flux (F1) before contamination, that is, F3 / F1.

[0137] The dynamic anti-pollution test conditions of the reverse osmosis membrane in the present invention are as follows:

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

[0139] F2 is the flux after F1 was measured, and the pollutants bovine serum albumin and polyoxyethylene 20 oleyl ether were added to the above sodium chloride aqueous solution to make the concentration of both 100 ppm, and continued to run for 2 hours;

[0140] F3 is the flux after the above F1 and F2 were measured, and the membrane was cleaned with a pH = 12.0 ± 0.5 NaOH solution for 12 hours, and then a 25°C, pH 7.0 ± 0.5, and sodium chloride concentration 2000ppm aqueous solution was cross-flow filtered at a pressure of 1.55 MPa for 1 hour.

[0141] 4. Membrane water contact angle test

[0142] The test was conducted using a water contact angle meter (Krüss DSA). The reverse osmosis membrane tested was dried in a vacuum oven at 80°C for 1 day. The test method was to drop 1 to 4 μL of deionized water onto the membrane surface, and calculate the water contact angle 10 seconds after the pure water dropped onto the membrane surface. Select a suitable test position, perform 5-point measurements, and calculate the average value.

[0143] 5. Hydrophilic polymer molecular weight test

[0144] Before testing, the hydrophilic polymer was precipitated from the mixed solution after polymerization using diethylene glycol dimethyl ether, and the precipitate was washed three times with ether, filtered, and vacuum dried to obtain the hydrophilic polymer.

[0145] The test was carried out by permeation gel chromatography (Shimadzu CTO-20A), using Shim-pack GPC-80M as the chromatographic column, Shim-pack GPC 800p as the guard column, tetrahydrofuran as the mobile phase, the flow rate was set to 1.0 mL / min, the column temperature was set to 50°C, the injection volume was set to 50 μL, the detector was a differential refractometer RID-10A, and 4 polyvinyl pyrrolidones with different molecular weights (PVP K16-18, K23-27, K29-32 and K88-96) were used as standards. A standard curve was drawn to determine the weight average molecular weight and molecular weight distribution value (PDI, the ratio of weight average molecular weight to number average molecular weight) of the hydrophilic polymer.

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

[0147] Before testing, the hydrophilic polymer was precipitated from the mixed solution after polymerization using diethylene glycol dimethyl ether, and the precipitate was washed three times with 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 and then placed in a nuclear magnetic resonance (HMR) sample tube. The HMR spectrum ( 1 H NMR). The test temperature was set at 20-25°C, and the cumulative number of measurements was 32 times. The spectrum results were analyzed using MestReNova software, and it was determined that the peaks at 2.7-4.0ppm came from the hydrogen on the C atoms on both sides of the N atom in vinyl pyrrolidone (3H) and the hydrogen on the C atoms on both sides of the N atom in N-methylallylamine (5H) or diallylamine (4H), and the peak at 2.2ppm came from the hydrogen on the carbon atom adjacent to the carbonyl group in vinyl pyrrolidone (2H). The baseline of each peak was determined by the software, and the peak area was integrated, where the peak area of ​​the hydrogen on the C atoms on both sides of the N atom is A C-N The peak area of ​​hydrogen on the carbon atom adjacent to the carbonyl group is A C＝O The actual pyrrolidone / amino molar ratio is calculated to be 5A C＝O / (2A C-N -3A C＝O ) (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 comprising a pyrrolidone segment and an amino segment:

[0149] Diblock hydrophilic polymer synthesis example 1

[0150] Vinyl pyrrolidone monomer and N-methylallylamine monomer were synthesized by free radical in a mass ratio of 90:10, with a solid content of 40%, a solvent of N-methylpyrrolidone, a reaction temperature of 78°C, an initiator of azobisisobutyronitrile in an amount of 0.5% of the total mass of the monomers, and a reaction time of 4 hours to obtain a diblock hydrophilic polymer 1. The final polymer had a weight average molecular weight of 61000, PDI=1.91, and an actual pyrrolidone / amino ratio of 7.4.

[0151] Synthesis Example 2 of Diblock Hydrophilic Polymer

[0152] Different from the diblock hydrophilic polymer synthesis example 1, vinyl pyrrolidone and N-methylallylamine were free radical synthesized at a mass ratio of 80:20 to obtain diblock hydrophilic polymer 2. The final polymer weight average molecular weight was 53,000, PDI=2.14, and the actual pyrrolidone / amino ratio was 3.4.

[0153] Synthesis Example 3 of Diblock Hydrophilic Polymer

[0154] Different from the diblock hydrophilic polymer synthesis example 1, vinyl pyrrolidone and N-methylallylamine were free radical synthesized at a mass ratio of 95:5 to obtain diblock hydrophilic polymer 3. The final polymer weight average molecular weight was 65,000, PDI = 2.26, and the actual pyrrolidone / amino ratio was 13.3.

[0155] Synthesis Example 4 of Diblock Hydrophilic Polymer

[0156] Different from the diblock hydrophilic polymer synthesis example 1, vinyl pyrrolidone and diallylamine were free radical synthesized at a mass ratio of 90:10 to obtain diblock hydrophilic polymer 4. The final polymer had a weight average molecular weight of 59,000, PDI = 2.05, and an actual pyrrolidone / amino ratio of 8.5.

[0157] Synthesis Example 5 of Diblock Hydrophilic Polymer

[0158] The difference from the diblock hydrophilic polymer synthesis example 1 is that the reaction temperature is 90°C, the initiator is dibenzoyl peroxide, the amount used is 0.5% of the total mass of the monomer, the reaction time is 4 hours, and the diblock hydrophilic polymer 5 is obtained. The final polymer weight average molecular weight is 57,000, PDI=2.13, and the actual pyrrolidone / amino ratio is 7.2.

[0159] Comparative Synthesis Example 1 of Hydrophilic Polymer

[0160] Free radical synthesis was carried out using vinyl pyrrolidone with a solid content of 40% by mass, the solvent was N-methylpyrrolidone, the reaction temperature was 78°C, the initiator was azobisisobutyronitrile, the amount used was 0.5% of the total mass of the monomer, the reaction time was 4 hours, and a hydrophilic polymer 1 was obtained. 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 anti-pollution polyamide reverse osmosis membrane with high organic matter removal is as follows:

[0163] Step 1: preparing a polysulfone ultrafiltration support layer on the surface of a polyethylene terephthalate non-woven fabric, specifically: preparing a polysulfone casting solution containing 16.5 wt% of a polysulfone resin in N,N-dimethylformamide; then applying the filtered and degassed polysulfone casting solution on the polyethylene terephthalate non-woven fabric; immediately immersing it in a coagulation bath deionized water to form a membrane through phase conversion, and then washing it with water to obtain a polysulfone ultrafiltration support layer, which is then cut into 16 cm×12 cm membrane sheets;

[0164] Step 2: dissolving m-phenylenediamine, camphorsulfonic acid and triethylamine in deionized water, stirring and mixing, and preparing an aqueous solution containing m-phenylenediamine at a concentration of 2.5wt%, camphorsulfonic acid at a concentration of 3.2wt%, and triethylamine at a concentration of 1.6wt%, wherein camphorsulfonic acid and triethylamine form a buffer to triethylamine camphorsulfonate, and the pH of the aqueous solution is about 11.5;

[0165] Step 3: dissolving trimesoyl chloride in isopar G isoparaffin, stirring and mixing evenly, and preparing an organic phase solution containing trimesoyl chloride at a concentration of 0.12 wt%;

[0166] Step 4: Glue the polysulfone ultrafiltration support layer membrane prepared in step 1 onto the plate frame with the surface facing upward, immerse it in the aqueous solution prepared in step 2 at 25°C for 60 seconds, then take out the plate frame and place it on the paper towel on top of the plastic plate, and gently squeeze it with a roller to remove the excess aqueous solution remaining on the surface, then contact it with the organic phase solution containing trimesoyl chloride in step 3, and react at 25°C for 30 seconds, pour out the excess organic phase solution, and then use an air knife to blow evenly until there is no residual solvent on the membrane surface, and then put it into an 80°C oven for heat treatment for 5 minutes. After taking it out of the oven, rinse the membrane surface with pure water until it is hydrophilic.

[0167] Step 5: The membrane surface obtained in step 4 is contacted with an aqueous solution of 0.1 wt% diblock hydrophilic polymer 1 and 0.5 wt% sodium dodecyl sulfate, and the grafting reaction is carried out at 25° C. for 30 seconds. After the excess solution is poured off, the membrane surface is washed with pure water.

[0168] Step 6: Place the membrane obtained in step 5 in a 0.1wt% aqueous solution of active allyl epoxy polyether KL-11B, perform a thermal crosslinking reaction at 80°C for 180 seconds, and finally take out the membrane and rinse it with pure water to obtain the anti-pollution polyamide reverse osmosis membrane with high organic matter removal of Example 1.

[0169] Example 2

[0170] The difference from Example 1 is that in step 5, an aqueous solution of 0.01 wt% diblock hydrophilic polymer 1 and 0.1 wt% sodium dodecyl sulfate is used, the grafting reaction is carried out at 25°C for 90 seconds, and other operations and conditions remain unchanged to obtain the anti-pollution polyamide reverse osmosis membrane with high organic matter removal of Example 2.

[0171] Example 3

[0172] The difference from Example 1 is that in step 5, an aqueous solution of 10.0 wt% diblock hydrophilic polymer 1 and 10.0 wt% sodium dodecyl sulfate is used, the grafting reaction is carried out at 25°C for 10 seconds, and other operations and conditions remain unchanged to obtain the anti-pollution polyamide reverse osmosis membrane with high organic matter removal of Example 3.

[0173] Example 4

[0174] The difference from Example 1 is that in step 5, an aqueous solution with a concentration of 0.1 wt % of diblock hydrophilic polymer 2 and 0.5 wt % of polyvinyl pyrrolidone K29-32 is used, and other operations and conditions remain unchanged, thereby obtaining the anti-pollution polyamide reverse osmosis membrane with high organic matter removal of Example 4.

[0175] Example 5

[0176] The difference from Example 1 is that in step 5, an aqueous solution with a concentration of 0.1 wt % of diblock hydrophilic polymer 3 and 0.5 wt % of Tween 80 is used, and other operations and conditions remain unchanged, thereby obtaining the anti-fouling polyamide reverse osmosis membrane with high organic matter removal of Example 5.

[0177] Example 6

[0178] The difference from Example 1 is that in step 5, an aqueous solution with a concentration of 0.1 wt % of diblock hydrophilic polymer 4 and 0.5 wt % of decyl glucoside is used, and other operations and conditions remain unchanged, thereby obtaining the anti-fouling polyamide reverse osmosis membrane with high organic matter removal of Example 6.

[0179] Example 7

[0180] The difference from Example 1 is that in step 5, an aqueous solution with a concentration of 0.01 wt % of diblock hydrophilic polymer 5 and 0.5 wt % of sodium dodecyl sulfate is used, and other operations and conditions remain unchanged, thereby obtaining the anti-pollution polyamide reverse osmosis membrane with high organic matter removal of Example 7.

[0181] Example 8

[0182] The difference from Example 1 is that in step 5, an aqueous solution of 0.1wt% diblock hydrophilic polymer 1 and 10.0wt% dodecyldimethylbenzyl ammonium bromide is used, the solution temperature is 60°C, and the grafting reaction is carried out for 10 seconds. In step 6, an aqueous solution of 0.1wt% allyl glycidyl ether is used, and other operations and conditions remain unchanged to obtain the anti-pollution polyamide reverse osmosis membrane with high organic matter removal of Example 8.

[0183] Example 9

[0184] The difference from Example 1 is that in step 5, an aqueous solution of 0.1wt% diblock hydrophilic polymer 1 and 0.01wt% coconut glucoside is used, the solution temperature is 10°C, and the grafting time is 600 seconds; in step 6, an aqueous solution of 0.1wt% polyethylene glycol diglycidyl ether is used, and other operations and conditions remain unchanged to obtain the anti-pollution polyamide reverse osmosis membrane with high organic matter removal of Example 10.

[0185] Example 10

[0186] The difference from Example 1 is that in step six, a 100°C aqueous solution of 2.0 wt% ethylene glycol diglycidyl ether is used, and the thermal crosslinking reaction is carried out for 30 seconds. Other operations and conditions remain unchanged, thereby obtaining the anti-pollution polyamide reverse osmosis membrane with high organic matter removal of Example 11.

[0187] Embodiment 11

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

[0189] Comparative Example 1

[0190] The difference from Example 1 is that the grafting reaction in step 5 and the thermal crosslinking reaction in step 6 are omitted, and other operations and conditions remain unchanged.

[0191] The membrane prepared in step 4 is washed with pure water to make it hydrophilic, thereby obtaining a reverse osmosis membrane of comparative example 1.

[0192] Comparative Example 2

[0193] The difference from Example 1 is that the thermal cross-linking reaction in step 6 is omitted, and other operations and conditions remain unchanged. The membrane prepared in step 5 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 5 is omitted, the membrane prepared in step 4 is taken out and rinsed with pure water to make it hydrophilic, and is directly used for the thermal crosslinking reaction in step 6, and other operations and conditions remain unchanged, thereby obtaining a reverse osmosis membrane of Comparative Example 3.

[0196] Comparative Example 4

[0197] The difference from Example 1 is that in step 5, the hydrophilic polymer 1 with a concentration of 10.0wt% and the sodium dodecyl sulfate solution with a concentration of 0.5wt% are used, and other operations and conditions remain unchanged, thereby obtaining the anti-pollution polyamide reverse osmosis membrane with high organic matter removal of Comparative Example 4.

[0198] Comparative Example 5

[0199] The difference from Example 1 is that according to the method of patent CN 113634130 A, in step 5, a methanol aqueous solution with a concentration of 2.0wt% polyvinylpyrrolidone K29-32 and 0.01wt% α-ketoglutaric acid (the volume ratio of methanol to water is 1:1) is used, the solution temperature is 25°C, the contact time is 20 seconds, and the membrane obtained in step 5 is subsequently placed under an ultraviolet lamp with a wavelength of 236nm, the membrane surface is 5cm away from the ultraviolet lamp, and after irradiation for 10 seconds, the anti-pollution polyamide reverse osmosis membrane of comparative example 5 is obtained.

[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 index data of the anti-fouling layer of the reverse osmosis membrane

[0202]

[0203]

[0204] From the experimental results in Table 2, it can be seen that compared with Comparative Example 1 without a hydrophilic polymer anti-pollution layer, the hydrophilicity of the membrane of the embodiment is better, the anti-pollution performance is more excellent, the initial separation performance is basically unchanged, and the isopropanol removal rate is improved, which has a good application prospect. Compared with Comparative Example 1, the hydrophilicity of the membrane of Comparative Example 2 is better, and the anti-pollution performance and isopropanol removal performance are also better, indicating that the single-grafted diblock hydrophilic polymer can also improve the anti-pollution and organic matter removal rate of the membrane. Compared with Comparative Example 1, the membrane of Comparative Example 3 has better isopropanol removal performance, indicating that the organic matter removal performance of the membrane can be improved by using only active allyl epoxy polyether.

[0205] The above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A high organic matter removal anti-pollution polyamide reverse osmosis membrane, characterized in that: It includes a polyester non-woven fabric layer, a polysulfone ultrafiltration support layer, a polyamide separation bottom membrane layer, and a hydrophilic polymer anti-pollution layer; The polyamide separation bottom membrane layer is a cross-linked polymer formed by interfacial polycondensation reaction of polyamine and polyacyl chloride; The hydrophilic polymer anti-pollution layer is a polymer formed by cross-linking reaction between a diblock hydrophilic polymer containing a pyrrolidone chain segment and an amino chain segment and a small molecule compound containing an epoxy group and / or an allyl group.

2. The anti-pollution polyamide reverse osmosis membrane with high organic matter removal according to claim 1, characterized in that: The polyester non-woven fabric layer is made of any one or a mixture of polyethylene terephthalate, polypropylene terephthalate and polybutylene terephthalate; Preferably, the polyester nonwoven fabric is a polyethylene terephthalate nonwoven fabric; and / or The polysulfone ultrafiltration support layer is a porous ultrafiltration membrane formed by coating a polysulfone material on a polyester nonwoven fabric layer, and its pore size is 1-100nm, preferably 1-50nm; its thickness is 20-150μm, preferably 30-80μm.

3. The anti-pollution 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 amine groups; preferably, the aromatic amine is selected from any one or a mixture of phenylenediamine or phenylenediamine, 1,3,5-triaminobenzene bonded to the benzene ring at the ortho, meta, or para positions, and the aliphatic amine is selected from any one or a mixture of ethylenediamine, propylenediamine, and piperazine; Preferably, the polyfunctional amine is m-phenylenediamine; and / or The polyacyl chloride is selected from aromatic and / or aliphatic polyacyl chlorides; preferably, the aromatic polyacyl chloride is selected from any one of trimesoyl chloride, terephthaloyl chloride, isophthaloyl chloride, and naphthalene dicarboxylic acid chloride, or a mixture thereof; and the aliphatic polyacyl chloride is selected from any one of malonyl chloride, succinyl chloride, adipoyl chloride, and 1,4-cyclohexanedicarboxylic acid chloride, or a mixture thereof; Preferably, the polyacid chloride is trimesoyl chloride.

4. The anti-pollution polyamide reverse osmosis membrane with high organic matter removal according to claim 1, characterized in that: The diblock hydrophilic polymer comprising a pyrrolidone segment and an amino segment has a weight average molecular weight in the range of 20,000 to 150,000 Da, preferably 40,000 to 80,000 Da; a weight average molecular weight and molecular weight distribution value (PDI) in the range of 1 to 5, preferably 1 to 3; an actual pyrrolidone / amino molar ratio in the range of 2 to 20, preferably 3 to 10; and / or The diblock hydrophilic polymer containing pyrrolidone chain segments and amino chain segments is a diblock copolymer synthesized by a free radical copolymerization method, and the synthetic monomers include pyrrolidone-containing monomers and amino-containing monomers; Preferably, the pyrrolidone-containing monomer is selected from any one of vinyl pyrrolidone, 3-allyl pyrrolidone-2-one, 3-(2-methylprop-2-enyl) pyrrolidone-2-one, 3-(3-butene-1-yl)-2-pyrrolidone, 3-(3-butene-1-yl)-3-(2-propene-1-yl)-2-pyrrolidone, 1-(1-propenyl) pyrrolidone-2-one or a mixture thereof, and more preferably vinyl pyrrolidone; Preferably, the amino-containing monomer is selected from any one or a mixture of N-methylallylamine, diallylamine, allylethylamine, 2-methylpropyleneamine, N-ethylmethylpropyleneamine, and allylamine, more preferably any one or a mixture of N-methylallylamine and diallylamine; Preferably, the feed mass ratio of the pyrrolidone-containing monomer to the amino-containing monomer is 95:5 to 75:25; Optionally, the diblock copolymer is synthesized by reacting in the presence of an initiator, wherein the initiator is selected from any one of azobisisobutyronitrile, azobisisoheptanenitrile, and benzoyl peroxide, or a mixture of several thereof, preferably azobisisobutyronitrile; preferably, the amount of the initiator is 0.01 to 5.0%, preferably 0.5 to 2.0%, of the total mass of the pyrrolidone-containing monomer and the amino-containing monomer; Optionally, the diblock copolymer is synthesized by reacting in a solvent environment, wherein the solvent is selected from any one 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, or a mixture thereof, preferably N-methylpyrrolidone; preferably, the amount of the solvent accounts for 20 to 99% of the total mass of the reaction system, more preferably 40 to 80%; Preferably, in the free radical copolymerization method, the reaction temperature is 50 to 100° C., preferably 70 to 90° C., and the reaction time is 0.5 to 24 hours, preferably 4 to 8 hours; and / or The small molecule compound containing epoxy and / or allyl groups is selected from any one 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, or a mixture of several of them, preferably any one of polyethylene glycol diglycidyl ether, allyl glycidyl ether, and active allyl epoxy polyether, or a mixture of several of them.

5. A method for preparing the high organic matter removal anti-pollution polyamide reverse osmosis membrane according to any one of claims 1 to 4, characterized in that: The method comprises the following steps: S1: obtaining a polysulfone ultrafiltration support layer on the surface of the polyester non-woven fabric layer; S2: immersing the polysulfone ultrafiltration support layer in an aqueous solution containing polyamine and additives for a period of time, and removing the aqueous solution remaining on the surface after taking it out; S3: contacting the surface of the polysulfone ultrafiltration support layer with an organic phase solution containing polyacid chlorides to perform interfacial polymerization reaction, reacting for a period of time, removing the organic phase solution remaining on the surface, and then performing heat treatment, and then washing with water until the membrane surface is hydrophilic to form a polyamide separation bottom membrane layer; S4: contacting the surface of the polyamide separation bottom membrane layer with an aqueous solution containing a diblock hydrophilic polymer including a pyrrolidone segment and an amino segment and a surfactant to carry out a grafting reaction, reacting for a period of time, removing the aqueous solution remaining on the surface, and then washing with water to obtain a polyamide separation bottom membrane layer grafted with the hydrophilic polymer; S5: The surface of the polyamide separation bottom membrane layer grafted with a hydrophilic polymer is brought into contact with an aqueous solution containing small molecule compounds containing epoxy groups and / or allyl groups to perform a thermal cross-linking reaction. After reacting for a period of time, the aqueous solution remaining on the surface is removed, and then the membrane is rinsed with water to obtain the anti-fouling polyamide reverse osmosis membrane with high organic matter removal.

6. The preparation method according to claim 5, characterized in that: In the aqueous solution of step S2, the concentration of the polyamine is 0.5-10.0 wt%, preferably 1.0-5.0 wt%; and / or In the aqueous solution of step S2, the concentration of the additive is 1.0 to 20.0 wt %; Preferably, the pH of the aqueous solution is 9.0 to 12.0; and / or The additive in step S2 is an acid acceptor, which is selected from a weak base, a buffer pair consisting of a weak base and an acid, or any one or a mixture of alkali metal hydroxides, carbonates and bicarbonates, and organic acid salts; Preferably, the weak base is selected from any one of triethylamine and sodium phosphate or a mixture of several thereof; the buffer pair composed of the weak base and the acid is selected from any one of triethylamine hydrochloride and triethylamine camphorsulfonate or a mixture of several thereof; the hydroxide, carbonate and bicarbonate of the alkali metal is selected from any one of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate and potassium bicarbonate or a mixture of several thereof; the organic compound is selected from any one of tetramethylammonium hydroxide and tetraethylammonium hydroxide or a mixture of several thereof; More preferably, the acid acceptor is triethylamine camphorsulfonate; More preferably, the aqueous solution in step S2 contains 1.1 to 3.5 wt % of triethylamine and 2.3 to 6.5 wt % of camphorsulfonic acid; and / or The residence time described in step S2 is 10 to 120 seconds.

7. The preparation method according to claim 5, characterized in that: In the organic phase solution of step S3, the concentration of polyacid chloride is 0.01-1.0 wt%, preferably 0.05-0.5 wt%; and / or In the organic phase solution described in step S3, the solvent is selected from any one of n-hexane, cyclohexane, n-heptane, n-decane, isoparaffin Isopar G, isoparaffin Isopar L or a mixture thereof, preferably any one of n-hexane, cyclohexane and isoparaffin Isopar G or a mixture thereof; and / or The interfacial polymerization reaction in step S3 is carried out at a temperature of 10 to 50° C., preferably 15 to 35° C., for a time of 10 to 60 seconds, preferably 30 to 60 seconds; and / or The heat treatment in step S3 is performed at a temperature of 50 to 120° C., preferably 60 to 100° C., for a time of 3 to 10 minutes, preferably 3 to 5 minutes.

8. The preparation method according to claim 5, characterized in that: In the aqueous solution described in step S4, the concentration of the diblock hydrophilic polymer comprising a pyrrolidone segment and an amino segment is 0.01 to 10.0 wt %, preferably 0.05 to 1.0 wt %; and / or In the aqueous solution described in step S4, the concentration of the surfactant is 0.01 to 10.0 wt%, preferably 0.10 to 1.0 wt%; and / or The surfactant described in step S4 is selected from any one or a mixture of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, hexadecyl ammonium bromide, dodecyltrimethylammonium bromide, dodecyldimethylbenzylammonium bromide, tetrabutylammonium bromide, coconut glucoside, lauryl glucoside, sucrose esters, polysorbate (Tween), polyoxyethylenes, polyoxyethylene-polyoxypropylene copolymers, and polyvinyl pyrrolidone, preferably any one or a mixture of sodium dodecyl sulfate, polyvinyl pyrrolidone and Tween 80; and / or The grafting reaction in step S4 has a reaction temperature of 10 to 60° C., preferably 20 to 40° C., and a reaction time of 10 to 600 seconds, preferably 30 to 180 seconds.

9. The preparation method according to claim 5, characterized in that: In the aqueous solution described in step S5, the concentration of the small molecule compound containing epoxy and / or allyl groups is 0.01 to 2.0 wt%, preferably 0.05 to 0.5 wt%; and / or The thermal cross-linking reaction in step S5 has a reaction temperature of 50 to 100° C., preferably 60 to 90° C., and a reaction time of 30 to 600 seconds, preferably 60 to 300 seconds.

10. Use of a high organic matter removal anti-pollution polyamide reverse osmosis membrane, the reverse osmosis membrane is prepared by the reverse osmosis membrane described in claims 1-4, or by the method described in any one of claims 5-9, and the reverse osmosis membrane is used in a water treatment component or a water treatment method.

Images