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CN-121775661-B - Reverse osmosis membrane for high-performance water treatment and preparation method and application thereof

CN121775661BCN 121775661 BCN121775661 BCN 121775661BCN-121775661-B

Abstract

The invention belongs to the technical field of membrane separation and water treatment, and particularly relates to a reverse osmosis membrane for high-performance water treatment, and a preparation method and application thereof. The invention provides a novel method for adding an interfacial regulator with octanol/water distribution coefficient Log P of-3-2 into an aqueous phase solution, adding functionalized long-chain fatty acid salt into an organic phase, forming a self-assembled layer by a long-carbon chain segment in the organic phase, maintaining a constant diffusion environment, regulating amine monomer migration by anions, stabilizing an interface by metal cations and enhancing the density of a film layer. Thereby realizing the precise regulation and control of interfacial polymerization kinetics from the organic phase side. The strategy can not only effectively improve the uniformity and compactness of the membrane layer, but also remarkably improve the boron removal and desalination performances while maintaining high water flux.

Inventors

  • PANG RUIZHI
  • WANG YI
  • ZHANG FENFANG
  • XU NANPING

Assignees

  • 苏州实验室
  • 中国乐凯集团有限公司

Dates

Publication Date
20260505
Application Date
20260305

Claims (10)

  1. 1. A preparation method of a reverse osmosis membrane for high-performance water treatment comprises the steps of sequentially contacting a porous base membrane with an aqueous phase solution and an organic phase solution to form a polyamide reverse osmosis membrane through interfacial polymerization, and is characterized in that an interfacial regulator with octanol/water distribution coefficient Log P of-3-2 is added into the aqueous phase solution, long-chain fatty acid salt with octanol/water distribution coefficient Log P of more than 0 is added into the organic phase solution, long-chain fatty acid salt anions are saturated or unsaturated fatty acid ions with C 15 –C 20 , cations are metal cations, and the surface of the polyamide reverse osmosis membrane has at least 75% nodular areas.
  2. 2. The method according to claim 1, wherein the long-chain fatty acid salt is a linear or branched hydrocarbon group containing 0 to 4 C=C or 0 to 1 C≡C, and the anion of the long-chain fatty acid salt is selected from any one or a combination of two or more of pentadecanoic acid, palmitic acid, palmitoleic acid, heptadecanoic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, stearidonic acid, nonadecanoic acid, arachic acid, eicosanoic acid, eicosadienoic acid, eicosatrienoic acid, and arachidonic acid, and the long-chain fatty acid salt has 0 to 3 functional groups selected from hydroxyl groups, carbonyl groups, ether groups, aldehyde groups, halogens, terminal alkenyl groups, terminal alkynyl groups, ester groups, and amide groups.
  3. 3. The preparation method according to claim 1, wherein the interface regulator is selected from one or a combination of two or more of camphorsulfonic acid, phosphoric acid, potassium bitartrate, ethanolamine, dimethyl sulfoxide, and citric acid.
  4. 4. The method of claim 1, wherein the long chain fatty acid salt is present in the organic phase solution at a concentration of 0.01 to 1wt%.
  5. 5. The method of claim 1, wherein the metal cation is one or more of Na + 、K + 、Ca 2+ 、Mg 2 + 、Zn 2+ 、Cu 2+ 、Fe 2+ or Fe 3+ .
  6. 6. The preparation method according to claim 1, wherein the concentration of the polyacyl chloride monomer in the organic phase solution is 0.01-5wt%, the polyacyl chloride monomer is selected from one or more of trimesoyl chloride, terephthaloyl chloride, isophthaloyl chloride, biphenyldicarboxyl chloride, biphenyltricarboxyl chloride, biphenyltetracarboxylic acid chloride, naphthalene dicarboxyl chloride, naphthalene tricarboxyl chloride, naphthalene tetracarboxylic acid chloride, malonyl chloride, succinyl chloride, glutaryl chloride, adipoyl chloride, the organic solvent in the organic phase solution is selected from one or more of hexane, heptane, octane, nonane, decane, undecane, dodecane, isopar C, isopar E, isopar G, isopar H, isopar L, isopar M, the aqueous phase solution contains a polyamine monomer, the concentration of the polyamine monomer in the aqueous phase solution is 0.5-5wt%, and the polyamine monomer is selected from one or more of o-phenylenediamine, M-phenylenediamine, 1,3, 5-diaminophenylenediamine, diaminotoluenediamine, diaminocyclohexane, and diaminocyclohexane.
  7. 7. The preparation method of the porous base membrane according to claim 1, wherein the time for the surface of the porous base membrane to contact with the aqueous phase solution is 1-300s, the time for the surface of the porous base membrane to contact with the organic phase solution is 1-300s, and the material of the porous base membrane is selected from one of polysulfone, polyphenylsulfone, polyethersulfone, polyvinylidene fluoride, polytetrafluoroethylene, polyethylene, polypropylene, polyimide, polyetherimide, polyacrylonitrile, polyphenyl ether, polyphenylene sulfide, polyetherketone and polyaryletherketone.
  8. 8. The method of claim 1, wherein the polyamide separation layer is subjected to a post-treatment selected from one or more of a diazotisation treatment, an acylation treatment, an amination treatment, or a surface graft modification after interfacial polymerization to form a polyamide reverse osmosis membrane.
  9. 9. A reverse osmosis membrane for high performance water treatment prepared according to the preparation method of claim 1.
  10. 10. The use of the reverse osmosis membrane for high performance water treatment according to claim 9 for desalination and debromination.

Description

Reverse osmosis membrane for high-performance water treatment and preparation method and application thereof Technical Field The invention belongs to the technical field of membrane separation and water treatment, and particularly relates to a reverse osmosis membrane for high-performance water treatment, and a preparation method and application thereof. Background Currently, sea water desalination technology has become an important way to obtain usable fresh water. Among them, the Reverse Osmosis (RO) membrane method has the advantages of low energy consumption, high quality of produced water, stable operation and the like, and becomes the main stream technology of sea water desalination. Most of the existing commercial reverse osmosis membranes are aromatic polyamide thin film composite membranes, and a separation layer is formed in an interfacial polymerization reaction by an aqueous phase aromatic diamine monomer (such as m-phenylenediamine, MPD) and an organic phase polybasic acyl chloride (such as trimesic chloride, TMC). The membrane can reach more than 99.5% in the aspect of salt rejection rate, but is insufficient in removing neutral small molecular boric acid (H 3BO3) in seawater. Therefore, improving the boron removal capacity of reverse osmosis membranes has been an important research direction in this field. In recent years, many researchers have tried to regulate the rate of interfacial polymerization reaction and the structure of the film layer by introducing a surfactant into an aqueous phase system. For example, common anionic surfactants such as Sodium Dodecyl Sulfate (SDS) and Sodium Dodecyl Benzene Sulfonate (SDBS) are widely used to improve the diffusion behavior and interfacial tension of aqueous monomers, thereby optimizing the compactness and surface morphology of the film to some extent. However, these control means mainly act on the aqueous phase side, and there is still insufficient research on the diffusion symmetry between the two phases of the interface and the influence of the organic phase reaction environment. Currently, surfactants are added in the organic phase to achieve reverse regulation of the interfacial polymerization process with little research. The prior art CN114247303A discloses that a nonionic surfactant is added into an oil phase solution, oil phase monomers are utilized to react with active groups on the nonionic surfactant, but polar groups (such as hydroxyl groups and ether bonds) and acyl chloride are subjected to side reaction, so that controllability and repeatability are reduced, and the prior art CN107126850A discloses that an anionic surfactant such as sodium dodecyl sulfate is added into a sulfonyl chloride organic phase solution to promote the reaction between two phases, so that the crosslinking degree is improved, but short-chain surfactants such as SDS (sodium dodecyl sulfate) have shorter carbon chain (C 12), have limited solubility in an organic phase and unstable interfacial adsorption, are easy to cause interface fluctuation and local polymerization, and have limited surface activity, more concentrated on one side of the water phase, and have limited monomer diffusion regulation effect on the organic phase. In addition, polyamide reverse osmosis membranes containing nodular structures have been demonstrated to have high rejection, and the ability to produce polyamide reverse osmosis membranes with nodular structures having high surface ratios is expected to increase rejection on the basis of increased membrane flux. Therefore, how to prepare a nodular polyamide reverse osmosis membrane with high surface ratio through interface regulation and control to have high rejection rate, high flux and high boron removal rate at the same time is a problem to be solved. Disclosure of Invention Aiming at the problems, the invention provides a novel method for adding functionalized long-chain fatty acid salt into an organic phase, wherein a long-carbon chain segment forms a self-assembled layer in the organic phase, maintains a constant diffusion environment, and anions regulate amine monomer migration, and metal cations stabilize an interface and enhance the density of a film layer. Thereby realizing the precise regulation and control of interfacial polymerization kinetics from the organic phase side. The strategy can not only effectively improve the uniformity and compactness of the membrane layer, but also remarkably improve the boron removal and desalination performances while maintaining high water flux. Specifically, the invention provides a preparation method of a reverse osmosis membrane for high-performance water treatment, which comprises the steps of sequentially contacting a porous base membrane with an aqueous phase solution and an organic phase solution to perform interfacial polymerization to form a polyamide reverse osmosis membrane, wherein an interfacial regulator with octanol/water distribution coefficient Log P of-3-2 is added into the