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CN-122006494-A - High-flux polyurea acid-resistant nanofiltration membrane and preparation method and application thereof

CN122006494ACN 122006494 ACN122006494 ACN 122006494ACN-122006494-A

Abstract

The invention discloses a high-flux polyurea acid-resistant nanofiltration membrane, and a preparation method and application thereof. The preparation method mainly comprises the steps of (1) preparing an aqueous phase solution containing an amine monomer and a catalyst, (2) soaking a base film into the aqueous phase solution for a certain time, taking out the base film, removing redundant aqueous phase, (3) preparing an isocyanate organic phase solution, (4) soaking the base film of (2) into the organic phase solution of (3) for a certain time, and (5) heating the obtained composite film for a certain time to obtain the high-flux polyurea acid-resistant nanofiltration membrane. The polyurea nanofiltration membrane prepared by the method has excellent acid resistance and higher permeation flux.

Inventors

  • LAN HONGLING
  • YAN KANGKANG
  • ZHAO WEIGUO

Assignees

  • 万华化学集团股份有限公司

Dates

Publication Date
20260512
Application Date
20241112

Claims (9)

  1. 1. The preparation method of the high-flux polyurea acid-resistant nanofiltration membrane is characterized by comprising the following specific steps of: (1) Preparing an aqueous phase solution of an amine monomer and a catalyst, and preparing an organic phase solution of isocyanate; (2) Soaking the base film into the aqueous phase solution for a certain time, taking out the base film, and removing redundant aqueous phase; (3) Soaking the base film into the organic phase solution for a certain time; (4) Heating the obtained composite membrane to obtain a high-flux polyurea acid-resistant nanofiltration membrane; Wherein the isocyanate is one or more of triphenylmethane triisocyanate, tetra (4-isocyanatobenzene) methane and 4,4 '-diisocyanate-5' - (4-isocyanatobenzene).
  2. 2. The method according to claim 1, wherein the amine monomer is one or more of 1,4,7, 10-tetraazacyclododecane, 1, 3-diaminoadamantane and polyethyleneimine, and the concentration of the amine monomer is preferably 0.05 to 3wt%.
  3. 3. The process according to claim 1, wherein the catalyst is one or more of 4-dimethylaminopyridine, pyrazine, 2, 6-lutidine and triethylamine, preferably the catalyst is present in a concentration of 0.01 to 0.5wt%.
  4. 4. The preparation method according to claim 1, wherein the solvent of the organic phase solution is chlorobenzene or chlorobenzene-benzene mixed solvent, preferably chlorobenzene-benzene mixed solvent, and the mass ratio of the chlorobenzene to the benzene mixed solvent is 1:1-5:1.
  5. 5. The process according to claim 1, wherein the isocyanate is present in the organic phase solution at a concentration of 0.05 wt.% to 0.2 wt.%.
  6. 6. The method according to claim 1, wherein the base film is immersed in the aqueous phase solution and the organic phase solution for 2 to 30 minutes.
  7. 7. The preparation method of claim 1, wherein the composite membrane in the step (4) is heated at 50-80 ℃ for 5-20min to obtain the high-flux polyurea acid-resistant nanofiltration membrane.
  8. 8. A high flux polyurea acid resistant nanofiltration membrane prepared by the method of any one of claims 1-7.
  9. 9. The use of the high flux polyurea acid resistant nanofiltration membrane of claim 8 in the field of wastewater treatment.

Description

High-flux polyurea acid-resistant nanofiltration membrane and preparation method and application thereof Technical Field The invention belongs to the technical field of water treatment membranes, and particularly relates to a high-flux polyurea acid-resistant nanofiltration membrane, and a preparation method and application thereof. Background In the industries of electroplating, metallurgy, titanium dioxide production and the like, a large amount of acid-containing wastewater is produced annually. Compared with the traditional wastewater treatment processes such as extraction, crystallization, evaporation and the like, the nanofiltration membrane separation technology has the advantages of low energy consumption, easiness in large-scale and the like, and has great application potential in the field of acidic wastewater treatment. However, conventional nanofiltration membranes are mainly composed of polyamide materials, which are easily hydrolyzed at lower pH, have poor acid resistance, and affect the long-term service life of the membrane materials. Wang et al (RSC ADVANCES,2019,9 (4): 2042-2054.) used 1, 3-benzenesulfonyl chloride and polyacrylamide to produce a polysulfonamide nanofiltration membrane with a flux of 68.2L m -2h-1MPa-1, a magnesium chloride rejection of 92.4%, and good acid resistance. He et al (Journal of MATERIALS SCIENCE,2019,54 (1): 886-900.) reacted with 1,4,7, 10-tetraazacyclododecane and 2,4, 6-tris (sulfonyl chloride) phenol to produce an acid-resistant nanofiltration membrane with a permeate flux of 13.98L m -2h-1MPa-1 and a copper sulfate rejection of 78%. However, the permeation flux of the acid-resistant nanofiltration membrane is low, and the treatment requirement of a large amount of acid-containing wastewater in industry is difficult to meet. Patent CN 113509839a and patent CN 115970521a provide a preparation method of a polyurea acid-resistant nanofiltration membrane, and a polyurea separation layer is obtained by interfacial polymerization of polyamine and polyisocyanate, but the water flux of the two patent nanofiltration membranes is still further improved. Disclosure of Invention The invention aims to overcome the defects of the prior art and provide a high-flux polyurea acid-resistant nanofiltration membrane which is obtained by reacting an isocyanate monomer with a space three-dimensional structure with amine. In order to achieve the above purpose, the technical scheme of the invention comprises the following steps: The invention aims at providing a preparation method of a high-flux polyurea acid-resistant nanofiltration membrane, which comprises the following steps: (1) Preparing an aqueous phase solution with the concentration of amine monomer of 0.05 to 3 weight percent and the concentration of catalyst of 0.01 to 0.5 weight percent; (2) Soaking the base film into the aqueous phase solution of the step (1) for 2-30min, taking out the base film, and removing redundant water drops; (3) Preparing an organic phase solution with the isocyanate concentration of 0.05 to 0.2 weight percent; (4) Soaking the base film of the step (2) into the organic phase solution of the step (3), and reacting for 2-30min; (5) And (3) putting the obtained composite membrane into an oven, and heating for 5-20min at 50-80 ℃ to obtain the high-flux polyurea acid-resistant nanofiltration membrane. Specifically, the catalyst in the step (1) is one or more of 4-dimethylaminopyridine, pyrazine, 2, 6-lutidine and triethylamine. The amine monomer in the step (1) is one or a mixture of more than one of 1,4,7, 10-tetraazacyclododecane, 1, 3-diaminoadamantane and polyethyleneimine, preferably a mixture of the amine monomer (1, 4,7, 10-tetraazacyclododecane and/or 1, 3-diaminoadamantane) with a space twist structure and polyethyleneimine. The base membrane in the step (2) is selected from one or more of polysulfone, polyethersulfone or polyacrylonitrile. The isocyanate in the step (3) is one or more of triphenylmethane triisocyanate (CAS# 2422-91-5), tetra (4-isocyanatobenzene) methane (CAS# 697746-87-5), 4 '-diisocyanate-5' - (4-isocyanatobenzene) (CAS# 865709-48-4). Specifically, the triphenylmethane triisocyanate has the structure shown as follows: Specifically, the tetrakis (4-isocyanatophenyl) methane structure is shown below: specifically, the structure of 4,4 '-diisocyanate-5' - (4-isocyanatobenzene) is shown below: Specifically, 4 '-diisocyanate-5' - (4-isocyanatobenzene) can be prepared by the synthetic method described in patent JP 2022173757. The solvent in the organic phase solution in the step (3) is chlorobenzene or chlorobenzene-benzene mixed solvent, and if chlorobenzene-benzene mixed solvent is selected, the mass ratio of the chlorobenzene to the benzene mixed solvent is preferably 1:1-5:1. The second purpose of the invention is to provide the high flux polyurea acid-resistant nanofiltration membrane prepared by the preparation method provided by the invention. The invention further aim