Search

CN-121972004-A - High-temperature-resistant antibacterial nanofiltration membrane and preparation method thereof

CN121972004ACN 121972004 ACN121972004 ACN 121972004ACN-121972004-A

Abstract

The invention discloses a high-temperature-resistant antibacterial nanofiltration membrane and a preparation method thereof, wherein the preparation method of the high-temperature-resistant antibacterial nanofiltration membrane comprises the following steps of dissolving polyacrylonitrile powder in a first organic solvent to obtain a polyacrylonitrile solution; adding an amination agent into a polyacrylonitrile solution, reacting for a period of time under a preset amination condition to obtain a uniform emulsion, collecting solid phase components in the emulsion to obtain colloid polymer particles, dissolving the colloid polymer particles and unmodified polyacrylonitrile powder in a second organic solvent according to a proportion to obtain a casting solution, preparing a composite base film on a non-woven fabric by the casting solution through a non-solvent induced phase separation method, immersing the composite base film into an aqueous phase solution, coating an oil phase monomer solution on the surface of the composite base film, performing interfacial polymerization reaction, and drying to form a polyamide functional layer on the surface of the composite base film to obtain the target high-temperature-resistant antibacterial nanofiltration membrane.

Inventors

  • LIN XIAOFENG
  • FENG FAN
  • WANG MENG

Assignees

  • 苏州普希环保科技有限公司

Dates

Publication Date
20260505
Application Date
20260211

Claims (10)

  1. 1. The preparation method of the high-temperature-resistant antibacterial nanofiltration membrane is characterized by comprising the following steps of: Dissolving polyacrylonitrile powder in a first organic solvent to obtain a polyacrylonitrile solution; adding an amination agent into the polyacrylonitrile solution, and reacting for a period of time under preset amination conditions to obtain a uniform emulsion; collecting the solid phase component in the emulsion to obtain colloidal polymer particles; The colloid polymer particles and unmodified polyacrylonitrile powder are dissolved in a second organic solvent together according to a proportion to obtain casting solution; preparing the casting solution on non-woven fabrics by a non-solvent induced phase separation method to obtain a composite base film; immersing the composite base film into an aqueous phase solution, coating an oil phase monomer solution on the surface of the composite base film, performing interfacial polymerization reaction, and drying to form a polyamide functional layer on the surface of the composite base film to obtain a target high-temperature-resistant antibacterial nanofiltration film; wherein the aqueous phase solution comprises an aqueous phase monomer and an ionic liquid.
  2. 2. The method for preparing the high-temperature-resistant antibacterial nanofiltration membrane according to claim 1, wherein the mass percentage of polyacrylonitrile in the polyacrylonitrile solution is 15% -18%.
  3. 3. The method for preparing a high temperature resistant antibacterial nanofiltration membrane according to claim 1, wherein the molar ratio of polyacrylonitrile in the polyacrylonitrile solution to the amination agent is 6:1.
  4. 4. The method for preparing a high temperature resistant antibacterial nanofiltration membrane according to claim 1, wherein the preset amination conditions comprise an amination temperature range of 90 ℃, an amination gas atmosphere of nitrogen and an amination time range of 3-6 hours.
  5. 5. The method for preparing a high temperature resistant antibacterial nanofiltration membrane according to claim 1, wherein the mass ratio of the colloidal polymer particles to the unmodified polyacrylonitrile powder in the membrane casting solution is 1:1.
  6. 6. The method for preparing a high temperature resistant antibacterial nanofiltration membrane according to claim 1, wherein the step of preparing a composite base membrane by a non-solvent induced phase separation method comprises the following operations: Scraping the casting film liquid on non-woven fabrics to prepare a wet film with the thickness of 100-200 microns, immersing the wet mill into a coagulating bath for phase inversion, obtaining the composite base film after the film is completely solidified, and storing the composite base film in deionized water for later use.
  7. 7. The method for preparing a high temperature resistant antibacterial nanofiltration membrane according to claim 1, wherein the aqueous phase monomer is at least one selected from piperazine, m-phenylenediamine, p-phenylenediamine, 3, 5-diaminobenzoic acid, ethylenediamine, propylenediamine, butylenediamine, pentylene diamine, hexylenediamine, and 4-aminomethylpiperazine; The ionic liquid is selected from one of 1-ethyl-3-methylimidazole lysine salt, 1-aminoethyl-3-methylimidazole tetrafluoroborate and 1-ethyl-3-methylimidazole acetate; the oil phase monomer in the oil phase monomer solution is trimesoyl chloride; The solvent of the oil phase monomer solution is selected from at least one of n-hexane or IsoparG.
  8. 8. The method for preparing the high temperature resistant antibacterial nanofiltration membrane according to claim 1, wherein the interfacial polymerization reaction comprises the steps of immersing the composite base membrane in an aqueous phase solution containing 1wt% to 10wt% of an aqueous phase monomer and 0.1wt% to 1wt% of an ionic liquid for 1 to 5min, removing the surplus aqueous phase by a roller, then pouring the solution into an oil phase solution containing 0.1wt% to 0.5wt% of an oil phase monomer, pouring the surplus oil phase after holding for 1 to 3min, and oven drying.
  9. 9. The method for preparing the high-temperature resistant antibacterial nanofiltration membrane according to claim 1, wherein the method comprises the steps of, The first organic solvent is at least one selected from N, N-dimethylacetamide, N-Dimethylformamide (DMF) and N-methylpyrrolidone; The amination agent is at least one selected from aromatic diamine or aliphatic diamine, wherein, The aromatic diamine includes phenylenediamine; The aliphatic diamine comprises at least one of ethylenediamine, 1, 6-diaminohexane, diethylenetriamine, propylenediamine, butylenediamine and m-aniline.
  10. 10. The high temperature resistant antibacterial nanofiltration membrane is characterized in that the high temperature resistant antibacterial nanofiltration membrane is prepared by adopting the preparation method of the high temperature resistant antibacterial nanofiltration membrane as claimed in any one of claims 1 to 9.

Description

High-temperature-resistant antibacterial nanofiltration membrane and preparation method thereof Technical Field The invention relates to the technical field of nanofiltration membranes, in particular to a high-temperature-resistant antibacterial nanofiltration membrane and a preparation method thereof. Background Nanofiltration (Nanofiltration, NF) membranes, which are a pressure-driven separation membrane between ultrafiltration and reverse osmosis, are widely used in the fields of water treatment, food processing, chemical separation, etc., due to their excellent properties in divalent ion removal, organic matter separation, water softening, etc. Currently, composite nanofiltration membranes with Polyamide (PA) as the selective layer are the mainstream products of the market, which are usually prepared on porous support layers by interfacial polymerization. However, in practical applications, especially in the context of high temperature industrial wastewater treatment or where high temperature disinfection is required, conventional nanofiltration membranes face serious challenges. In the prior art, polyacrylonitrile (PAN) is often used as a supporting layer material, but a PAN base film has the problem of insufficient heat resistance. When the temperature is increased, the polymer chain segment movement is increased, so that the structure of the supporting layer is relaxed, the pore diameter is increased, and the mechanical strength is reduced. More importantly, the polyamide selective layer and the PAN supporting layer are combined by mainly relying on physical acting force (such as Van der Waals force and mechanical interlocking) and lack of chemical bonding. Under a high-temperature environment, the two layers of materials generate internal stress due to different thermal expansion coefficients, delamination, foaming and other phenomena are easy to occur, the membrane flux is greatly attenuated and the rejection rate is obviously reduced, and the application of the nanofiltration technology under the high-temperature working condition is severely limited. In addition, in these applications, the membrane surface is likely to grow bacteria due to the substances such as proteins contained in the wastewater during long-term operation. Therefore, development of a nanofiltration membrane with excellent high temperature resistance is important. Disclosure of Invention The technical problem to be solved by the embodiment of the invention is to provide the high-temperature-resistant antibacterial nanofiltration membrane and the preparation method thereof, which can improve the high-temperature resistance and the antibacterial performance of the nanofiltration membrane. The invention provides a preparation method of a high-temperature-resistant antibacterial nanofiltration membrane, which comprises the following steps of dissolving polyacrylonitrile powder in a first organic solvent to obtain a polyacrylonitrile solution, adding an amination agent into the polyacrylonitrile solution, reacting for a period of time under a preset amination condition to obtain a uniform emulsion, collecting solid phase components in the emulsion to obtain colloid polymer particles, dissolving the colloid polymer particles and unmodified polyacrylonitrile powder in a second organic solvent together in proportion to obtain a casting solution, preparing the casting solution on a non-woven fabric by a non-solvent induced phase separation method to obtain a composite base membrane, immersing the composite base membrane into an aqueous phase solution, coating an oil phase monomer solution on the surface of the composite base membrane, performing interfacial polymerization reaction, and drying to form a polyamide functional layer on the surface of the composite base membrane to obtain the target high-temperature-resistant antibacterial nanofiltration membrane, wherein the aqueous phase solution comprises an aqueous phase monomer and an ionic liquid. In one possible implementation, the mass percent of polyacrylonitrile in the polyacrylonitrile solution ranges from 15% to 18%. In one possible implementation, the molar ratio of polyacrylonitrile in the polyacrylonitrile solution to the amination agent is 6:1. In one possible implementation, the preset amination conditions comprise an amination temperature range of 90 ℃ and an amination gas atmosphere of nitrogen, and the amination time range is 3-6 hours. In one possible implementation, the mass ratio of colloidal polymer particles to unmodified polyacrylonitrile powder in the casting solution is 1:1. In one possible implementation, the step of preparing the composite base film by the non-solvent induced phase separation method comprises the following operations of scraping the casting film liquid on non-woven fabrics to prepare a wet film with the thickness of 100-200 microns, immersing the wet mill into a coagulating bath for phase inversion, obtaining the composite base film after the fi