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CN-121972029-A - Composite reverse osmosis membrane material and preparation method and application thereof

CN121972029ACN 121972029 ACN121972029 ACN 121972029ACN-121972029-A

Abstract

The application discloses a composite reverse osmosis membrane material, and a preparation method and application thereof, and belongs to the technical field of reverse osmosis membrane preparation. The composite reverse osmosis membrane material comprises a polyolefin-based membrane and a polyamide layer formed on the polyolefin-based membrane, wherein a cross-linked network of the polyamide layer contains amino-polyethylene glycol-carboxyl transition metal salt. According to the composite reverse osmosis membrane material, the amino-polyethylene glycol-carboxyl transition metal salt is chemically introduced into the cross-linked network of the polyamide layer, so that small molecules of compounds such as sulfur, nitrogen and the like generated by microbial metabolism in the composite reverse osmosis membrane are effectively reduced, the technical problems that the existing reverse osmosis water purifier is not used for a few days or even longer, peculiar smell and odor are generated in pure water after the reverse osmosis water purifier is started again are solved, the operation of a rear active carbon filter element is omitted, and the cost is saved.

Inventors

  • WANG XUNING
  • ZHANG RAN
  • ZHOU YANG
  • LIU HAILIANG

Assignees

  • 杭州九阳小家电有限公司

Dates

Publication Date
20260505
Application Date
20241025

Claims (10)

  1. 1. The composite reverse osmosis membrane material is characterized by comprising a polyolefin-based membrane and a polyamide layer formed on the polyolefin-based membrane, wherein a cross-linked network of the polyamide layer contains amino-polyethylene glycol-carboxyl transition metal salt.
  2. 2. The composite reverse osmosis membrane material according to claim 1, wherein the amino-polyethylene glycol-carboxyl transition metal salt is at least one selected from the group consisting of the amino-polyethylene glycol-carboxyl zinc salt, the amino-polyethylene glycol-carboxyl iron salt, and the amino-polyethylene glycol-carboxyl copper salt.
  3. 3. The composite reverse osmosis membrane material according to claim 2, wherein the amino-polyethylene glycol-carboxyl transition metal salt is selected from the amino-polyethylene glycol-carboxyl zinc salt.
  4. 4. The composite reverse osmosis membrane material according to claim 1, wherein the polymerization degree of polyethylene glycol segment in the amino-polyethylene glycol-carboxyl transition metal salt is 2 to 25.
  5. 5. The composite reverse osmosis membrane material according to claim 4, wherein the polymerization degree of polyethylene glycol segment in the amino-polyethylene glycol-carboxyl transition metal salt is 5 to 12.
  6. 6. The method for preparing a composite reverse osmosis membrane material according to any one of claims 1 to 5, comprising the steps of: (1) Coating or infiltrating a solution containing amine monomers and amino-polyethylene glycol-carboxyl transition metal salt on a polyolefin-based film, wherein the amine monomers are cyclic monomers containing at least two amino groups; (2) And (3) carrying out interfacial reaction on the polyolefin-based membrane coated or infiltrated in the step (1) and a solution containing trimesic acid chloride to form a polyamide layer, and drying to obtain the composite reverse osmosis membrane material.
  7. 7. The method according to claim 6, wherein the concentration of the amine monomer in the solution containing the amine monomer and the amino-polyethylene glycol-carboxyl transition metal salt is 1wt% to 5wt%, the concentration of the amino-polyethylene glycol-carboxyl transition metal salt is 0.2wt% to 1.1wt%, the concentration of the surfactant is 0.02wt% to 0.2wt%, and the balance is water, and the pH is 9 to 11.
  8. 8. The method for preparing a composite reverse osmosis membrane material according to claim 6, wherein the concentration of trimesic acid chloride in the solution containing trimesic acid chloride is 0.1-0.5wt%.
  9. 9. The method for preparing a composite reverse osmosis membrane material according to claim 6, wherein the interfacial reaction time in the step (2) is 0.5-1min.
  10. 10. Use of a composite reverse osmosis membrane material according to any one of claims 1 to 5 or a composite reverse osmosis membrane material prepared by a method for preparing a composite reverse osmosis membrane material according to any one of claims 6 to 9 in a water purification apparatus.

Description

Composite reverse osmosis membrane material and preparation method and application thereof Technical Field The application relates to a composite reverse osmosis membrane material, a preparation method and application thereof, and belongs to the technical field of reverse osmosis membrane preparation. Background The reverse osmosis water purifier mainly relies on a reverse osmosis membrane to filter harmful substances, and the traditional reverse osmosis membrane is mainly based on a polyester non-woven fabric and a polysulfone layer as a base membrane, and a polyamide desalting layer is formed by interfacial polymerization on the base membrane to form a reverse osmosis membrane with a three-layer structure. However, the thickness of the reverse osmosis membrane is large, generally about 120 mu m, the pores in the membrane layer are developed, microorganisms are easy to breed, and the pure water has peculiar smell and poor taste. Especially when the reverse osmosis water purifier is not used for a few days or longer, obvious peculiar smell and even stink can appear when the water purifier is started again. The main reason for the occurrence of the situation is that the oxygen content in water is low, anaerobic bacteria or facultative anaerobic bacteria are rapidly propagated, small molecules containing sulfur and nitrogen atoms, such as small molecules of hydrogen sulfide, methyl mercaptan, thioester, thioether, ammonia and the like, are generated by metabolism while anaerobic respiration is carried out, and the reverse osmosis membrane has poor effect on the removal rate of small molecular gaseous substances, so that the small molecular compounds containing sulfur and nitrogen are the reason for causing the odor of pure water of the water purifier. Moreover, the odor threshold value of the substances is very low, for example, the minimum odor threshold value of hydrogen sulfide in water can be as low as 0.025 mug/L, and the water quality can be odorized by trace substances. At present, the reverse osmosis water purifier mainly uses the self-water for a long time to wash or adds the post-activated carbon to adsorb peculiar smell and improve the taste, but the activated carbon adsorption is physical adsorption, which belongs to reversibility, the adsorption is followed by desorption into water, the activated carbon is also a porous material, bacteria can be bred to cause peculiar smell for a long time, and in addition, the post-activated carbon filter element also occupies the space of the water purifier. The problem of odor after long-time non-use of the water purifier is solved by regularly flushing the rear filter element in the patent CN202322518U, so that the design of the water purifier becomes complex and water is wasted. In the patent CN115569538A, CN113797774a, bacteria are inhibited by grafting an antibacterial agent on the surface of the reverse osmosis membrane, but the surface of the reverse osmosis membrane is covered by scale, organic pollutants and the like after the reverse osmosis membrane is used for a period of time, so that the effect of the antibacterial agent is invalid, bacteria can be continuously propagated, and peculiar smell is generated. Disclosure of Invention In order to solve the problems, the composite reverse osmosis membrane material is provided, and through introducing amino-polyethylene glycol-carboxyl transition metal salt into a cross-linked network of a polyamide layer, the composite reverse osmosis membrane material effectively reduces sulfur-containing, nitrogen-containing and other small molecules generated by microbial metabolism in water after the composite reverse osmosis membrane filtration, solves the technical problems that the existing reverse osmosis water purifier is not used for a few days or even longer, the pure water has peculiar smell and stink after being restarted, omits the operation of a rear active carbon filter element, and saves the cost. According to an aspect of the present application, there is provided a composite reverse osmosis membrane material comprising a polyolefin-based membrane and a polyamide layer formed on the polyolefin-based membrane, the polyamide layer having an amino-polyethylene glycol-carboxyl transition metal salt in a crosslinked network. The amino group in the amino-polyethylene glycol-carboxyl transition metal salt participates in the crosslinking reaction of the polyamide layer, so that the amino-polyethylene glycol-carboxyl transition metal salt can be fixed in the composite reverse osmosis membrane material, and the transition metal ion in the amino-polyethylene glycol-carboxyl transition metal salt can carry out coordination reaction with sulfur-containing and nitrogen-containing peculiar smell small molecules, so that the peculiar smell small molecules are fixed on the amino-polyethylene glycol-carboxyl transition metal salt, and the adsorption of the sulfur-containing and nitrogen-containing peculiar smell small m