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CN-122011807-A - Zwitterionic modified titanium dioxide and preparation method thereof

CN122011807ACN 122011807 ACN122011807 ACN 122011807ACN-122011807-A

Abstract

The application discloses zwitterionic modified titanium dioxide and a preparation method thereof, wherein the titanium dioxide comprises a titanium dioxide substrate and a coating layer positioned on the surface of the titanium dioxide substrate, the coating layer comprises a Zn 2+ -amino acid type zwitterionic complex film layer, the Zn 2+ -amino acid type zwitterionic complex film layer is generated in situ through amino acid type zwitterions and a Zn source, and the amino acid type zwitterions are selected from at least one compound meeting the following structural general formula, wherein R' is an alkyl chain of C 8 ~C 18 . The modified titanium dioxide provided by the application still has good dispersion stability and antibacterial property under the conditions of higher humidity and wider pH range, the coverage of the titanium dioxide is further improved by improving the dispersion stability, and the problem of collaborative optimization of the titanium dioxide in the aspects of dispersion stability, coverage and antibacterial property in the prior art is effectively solved.

Inventors

  • ZHANG YURONG
  • HU JIETAO
  • DU JINGWEI
  • SHI WENCHEN
  • LI RUIRUI
  • HE LINRU
  • ZHANG LU
  • XU RAN

Assignees

  • 龙佰集团股份有限公司

Dates

Publication Date
20260512
Application Date
20251219

Claims (10)

  1. 1. The zwitterionic modified titanium dioxide is characterized by comprising a titanium dioxide matrix and a coating layer positioned on the surface of the titanium dioxide matrix; The coating layer comprises a Zn 2+ -amino acid type zwitterionic complex film layer, and the Zn 2+ -amino acid type zwitterionic complex film layer is generated in situ through amino acid type zwitterions and a Zn source; The amino acid type zwitterion is selected from at least one compound meeting the following structural general formula: R'–CO–NR–CH(X)–COO - M + ; wherein R' is an alkyl chain of C 8 ~C 18 .
  2. 2. The zwitterionic modified titanium dioxide of claim 1, wherein, The titanium dioxide matrix is anatase titanium dioxide or rutile titanium dioxide, and the particle size is 200-300 nm.
  3. 3. The zwitterionic modified titanium dioxide of claim 1, wherein, X is H, CH 3 or CH 2 CH 2 COOH, M is Na + 、K + 、NH 4 + or TEA + , and R is H or CH 3 .
  4. 4. The zwitterionic modified titanium dioxide of claim 1, wherein, The coating layer also comprises an inorganic coating layer positioned on the inner side of the Zn 2+ -amino acid type zwitterionic complex film layer.
  5. 5. The zwitterionic modified titanium dioxide of claim 1, wherein, The zinc source is at least one selected from zinc nitrate, zinc chloride, zinc sulfate or zinc acetate.
  6. 6. The zwitterionic modified titanium dioxide of claim 1, wherein, The dosage of the zinc source is 0.1-1% of the mass of the titanium dioxide matrix by zinc ion; The dosage of the amino acid type zwitterionic is 0.1-2% of the mass of the titanium dioxide matrix.
  7. 7. A method for preparing the zwitterionic modified titanium dioxide according to any one of claims 1 to 6, comprising the steps of: S1, dispersing titanium dioxide which is not modified by amphoteric ions in a pH buffer solution containing carboxylate radicals, and carrying out pretreatment to expose Ti-OH sites on the surface; S2, adding amino acid type amphoteric ions, and reacting with the titanium dioxide to form Ti-OOC-coordination bonds; S3, adding a zinc source, and carrying out a complexing reaction with the amino acid type zwitterionic residues to obtain the Zn 2+ -amino acid type zwitterionic complex film.
  8. 8. The method for preparing the zwitterionic modified titanium dioxide according to claim 7, wherein, The pH buffer solution in the step S1 is at least one selected from a citric acid buffer solution, a tartaric acid buffer solution, an oxalic acid buffer solution, an EDTA buffer solution and an acetic acid buffer solution, wherein the concentration of the buffer in the pH buffer solution is 0.01-0.1 mol/L; The pH of the pH buffer solution is 5.5-6.5, the pretreatment is that ultrasonic is carried out for 0.5-1.5 h at 50-70 ℃, and the ultrasonic power is 200-400W.
  9. 9. The method for preparing the zwitterionic modified titanium dioxide according to claim 7, wherein, And the reaction temperature in the step S2 is 50-70 ℃ and the reaction time is 2-5 h.
  10. 10. The method for preparing the zwitterionic modified titanium dioxide according to claim 7, wherein, And step S3, the reaction temperature is 50-70 ℃ and the reaction time is 1-3 h.

Description

Zwitterionic modified titanium dioxide and preparation method thereof Technical Field The invention belongs to the technical field of titanium dioxide preparation, and particularly relates to zwitterionic modified titanium dioxide and a preparation method thereof. The modified titanium dioxide can obviously improve the dispersion stability, optical hiding power and antibacterial property of the coating, and is suitable for the fields of building coatings, industrial anticorrosive coatings, ship coatings, medical antibacterial coatings and the like. Background The traditional titanium dioxide (TiO 2) is easy to agglomerate due to high surface energy in the application of the paint, so that the problems of sedimentation and uneven gloss of a coating film occur when the storage period is less than or equal to 3 months, and the modification (such as KH-570) of the traditional silane coupling agent can improve the dispersibility, is sensitive to humidity (> 60% failure) and is only suitable for a narrow pH range. The covering power of the titanium dioxide depends on the high refractive index (rutile type 2.71), but the refractive index can be reduced to less than or equal to 2.65 by conventional inorganic coating (such as SiO 2/Al2O3) to cause 10-15% covering power loss, the common TiO 2 has antibacterial property only by ultraviolet excitation, the common Ag load modification not only increases the cost by more than 30%, but also has the problem of metal ion migration, the betaine type amphoteric ion modification adopted by the patent CN110845032A improves the dispersibility, but the quaternary ammonium group structure is easy to degrade when the pH value is more than 9 and has less than 70% of gram-negative bacteria inhibition ratio, and the prior art cannot effectively solve the problem of cooperative optimization of the titanium dioxide in the aspects of dispersion stability, covering power and antibacterial property. Disclosure of Invention The invention aims to provide zwitterionic modified titanium dioxide and a preparation method thereof for solving the defects in the prior art. The invention aims at realizing the following technical scheme: the application provides zwitterionic modified titanium dioxide, which comprises a titanium dioxide matrix and a coating layer positioned on the surface of the titanium dioxide matrix; The coating layer comprises a Zn 2+ -amino acid type zwitterionic complex film layer, and the Zn 2+ -amino acid type zwitterionic complex film layer is generated in situ through amino acid type zwitterions and a Zn source; The amino acid type zwitterion is selected from at least one compound meeting the following structural general formula: R'–CO–NR–CH(X)–COO-M+; wherein R' is an alkyl chain of C 8~C18. Preferably, the titanium dioxide matrix is anatase titanium dioxide or rutile titanium dioxide, and the particle size is 200-300 nm. Preferably, X is selected from H, CH 3 or CH 2CH2 COOH, M is selected from Na +、K+、NH4+ or TEA +, and R is selected from H or CH 3. Preferably, the coating layer further comprises an inorganic coating layer positioned on the inner side of the Zn 2+ -amino acid type zwitterionic complex film layer. Preferably, the zinc source is at least one selected from zinc nitrate, zinc chloride, zinc sulfate or zinc acetate. Preferably, the zinc source is used in an amount of 0.1-1% of the mass of the titanium dioxide matrix based on zinc ions; The dosage of the amino acid type zwitterionic is 0.1-2% of the mass of the titanium dioxide matrix. The second aspect of the application provides a preparation method of the zwitterionic modified titanium dioxide, which comprises the following steps: S1, dispersing titanium dioxide which is not modified by amphoteric ions in a pH buffer solution containing carboxylate radicals, and carrying out pretreatment to expose Ti-OH sites on the surface; S2, adding amino acid type amphoteric ions, and reacting with the titanium dioxide to form Ti-OOC-coordination bonds; S3, adding a zinc source, and carrying out a complexing reaction with the amino acid type zwitterionic residues to obtain the Zn 2+ -amino acid type zwitterionic complex film. Preferably, the pH buffer solution in the step S1 is at least one selected from a citric acid buffer solution, a tartaric acid buffer solution, an oxalic acid buffer solution, an EDTA buffer solution and an acetic acid buffer solution, wherein the concentration of the buffer in the pH buffer solution is 0.01-0.1 mol/L; The pH of the pH buffer solution is 5.5-6.5, the pretreatment is that ultrasonic is carried out for 0.5-1.5 h at 50-70 ℃, and the ultrasonic power is 200-400W. Preferably, the reaction temperature in the step S2 is 50-70 ℃ and the reaction time is 2-5 h. Preferably, the reaction temperature in the step S3 is 50-70 ℃ and the reaction time is 1-3 h. The modified titanium dioxide provided by the application still has good dispersion stability and antibacterial property under the conditio