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CN-121972032-A - Modified graphene oxide film and preparation method and application thereof

CN121972032ACN 121972032 ACN121972032 ACN 121972032ACN-121972032-A

Abstract

The invention provides a modified graphene oxide membrane and a preparation method and application thereof, and belongs to the technical field of pervaporation membranes. The preparation method of the modified graphene oxide film comprises the following steps of (1) uniformly mixing graphene oxide aqueous dispersion liquid and covalent organic framework material powder dispersion liquid to obtain a mixed solution, (2) adding deionized water into the mixed solution obtained in the step (1), uniformly stirring, adjusting the pH of a system to 7.8-8.5, performing ultrasonic treatment, depositing the dispersion liquid subjected to ultrasonic treatment on a PAN base film through positive pressure filtration, and performing heat treatment to obtain the modified graphene oxide film. The modified graphene oxide membrane prepared by the method has good isopropanol dehydration performance and structural stability, and provides a new thought for improving the isopropanol dehydration performance and structural stability of the GO-based separation membrane.

Inventors

  • LIAO MINGJIA
  • GONG GENGHAO

Assignees

  • 重庆化工职业学院

Dates

Publication Date
20260505
Application Date
20260403

Claims (10)

  1. 1. The preparation method of the modified graphene oxide film is characterized by comprising the following steps of: (1) Uniformly mixing graphene oxide aqueous dispersion and covalent organic framework material powder dispersion to obtain a mixed solution; (2) Adding deionized water into the mixed solution obtained in the step (1), uniformly stirring, regulating the pH of the system to 7.8-8.5, performing ultrasonic treatment, depositing the dispersion liquid after ultrasonic treatment on a PAN (PAN) base film through positive pressure filtration, and performing heat treatment to obtain the modified graphene oxide film.
  2. 2. The method for producing a modified graphene oxide film according to claim 1, wherein the mass concentration of the aqueous graphene oxide dispersion in the step (1) is 0.1 to 0.3mg/mL.
  3. 3. The method for producing a modified graphene oxide film according to claim 1, wherein the mass concentration of the covalent organic framework material powder dispersion in the step (1) is 0.5 to 0.8mg/mL.
  4. 4. The method for preparing a modified graphene oxide film according to claim 1, wherein the mass ratio of graphene oxide to covalent organic framework material powder is 1:1-2.
  5. 5. The method for preparing a modified graphene oxide film according to claim 1, wherein the method for preparing the covalent organic framework material powder dispersion comprises the following steps: (1) Mixing 1,3, 5-tri (4-aminophenyl) benzene, 2, 6-dialdehyde-1, 5-dihydroxynaphthalene and mesitylene, performing ultrasonic treatment to obtain a mixture, placing the mixture into a reaction kettle, adding acetic acid solution into the reaction kettle, heating to 80-100 ℃, and preserving heat for 72-120 hours to obtain an intermediate; (2) Dispersing the covalent organic framework material powder in N, N-dimethylformamide, and carrying out ultrasonic treatment to obtain a covalent organic framework material powder dispersion liquid.
  6. 6. The method for producing a modified graphene oxide film according to claim 5, wherein the mass ratio of the 1,3, 5-tris (4-aminophenyl) benzene, 2, 6-dialdehyde-1, 5-dihydroxynaphthalene, mesitylene and acetic acid solution in the step (1) is 7-9:6-8:1-1.5:3-5, and the molar concentration of the acetic acid solution in the step (1) is 1-3mol/L.
  7. 7. The method for producing a modified graphene oxide film according to claim 1, wherein the pH of the system is adjusted in step (2) using 0.1M NaOH.
  8. 8. The method for producing a modified graphene oxide membrane according to claim 1, wherein the pressure of the positive pressure filtration in the step (2) is 6 to 8 bar.
  9. 9. The modified graphene oxide film prepared by the method according to any one of claims 1 to 8.
  10. 10. The modified graphene oxide film prepared by the method according to any one of claims 1 to 8, or the application of the modified graphene oxide film according to claim 9 in the field of organic solvent dehydration recycling.

Description

Modified graphene oxide film and preparation method and application thereof Technical Field The invention relates to the technical field of pervaporation membranes, in particular to a modified graphene oxide membrane and a preparation method and application thereof. Background In chemical synthesis and drug production processes, organic solvents are widely used in synthesis reactions and purification processes of products, and high-purity solvents are generally required to ensure process quality, but after single use, the solvents often cannot be directly recycled due to moisture or other impurities. The waste water containing a large amount of organic matters is directly discharged without treatment, so that resources are wasted, and the environment is seriously polluted. Therefore, development of efficient dehydration technology to realize recycling of solvent has important significance in promoting green manufacturing and sustainable development. In the field of chemical industry, the pervaporation technology shows a better separation effect for the separation of azeotropic systems or near-boiling mixtures which are difficult to treat by conventional technical means. Pervaporation technology relies on the selective adsorption and diffusion properties of components on the membrane surface to achieve separation. As one of membrane separation technologies, the pervaporation technology has the core advantages of compact equipment, high recovery efficiency, flexible device adaptation and the like, and has the characteristics of good economy, high safety, environmental friendliness and the like when treating liquid mixtures. Thus, pervaporation is considered to be a potential alternative to traditional high-energy separation processes such as extractive distillation, azeotropic distillation, and the like. The pervaporation membrane can be divided into an organic membrane, an inorganic membrane, a two-dimensional material membrane and an organic-inorganic composite membrane according to materials. The organic polymer film has good film forming property, high flexibility and lower cost, and the polar group can form hydrogen bond with water molecules, which is favorable for selective adsorption and dehydration, but has poor high temperature and high pressure resistance and solvent swelling resistance and limited stability. The inorganic film has excellent thermal stability, mechanical strength and solvent resistance, but has higher preparation cost and restricts large-scale application. Two-dimensional material films such as graphene oxide films are novel film materials, a lamellar structure with atomic-level thickness can be used for constructing an ultrathin separation layer, high permeability and selectivity are realized through lamellar defects and interlayer channels, and the two-dimensional material films are widely applied to the field of organic solvent dehydration at present. However, the graphene oxide membrane is easy to absorb water and swell due to the existence of oxygen-containing groups at the edge of the sheet layer, so that the separation performance and water flux of the separation membrane are affected. Disclosure of Invention In view of the above, the present invention provides a method for preparing a modified graphene oxide film, comprising the steps of: (1) Uniformly mixing graphene oxide aqueous dispersion and covalent organic framework material powder dispersion to obtain a mixed solution; (2) Adding deionized water into the mixed solution obtained in the step (1), uniformly stirring, regulating the pH of the system to 7.8-8.5, performing ultrasonic treatment, depositing the dispersion liquid after ultrasonic treatment on a PAN (PAN) base film through positive pressure filtration, and performing heat treatment to obtain the modified graphene oxide film. Further, the mass concentration of the graphene oxide aqueous dispersion liquid in the step (1) is 0.1-0.3mg/mL. Further, the mass concentration of the covalent organic framework material powder dispersion liquid in the step (1) is 0.5-0.8mg/mL. Further, the mass ratio of the graphene oxide to the covalent organic framework material powder is 1:1-2. Further, the preparation method of the covalent organic framework material powder dispersion liquid comprises the following steps: (1) Mixing 1,3, 5-tri (4-aminophenyl) benzene, 2, 6-dialdehyde-1, 5-dihydroxynaphthalene and mesitylene, performing ultrasonic treatment to obtain a mixture, placing the mixture into a reaction kettle, adding acetic acid solution into the reaction kettle, heating to 80-100 ℃, and preserving heat for 72-120 hours to obtain an intermediate; (2) Dispersing the covalent organic framework material powder in N, N-dimethylformamide, and carrying out ultrasonic treatment to obtain a covalent organic framework material powder dispersion liquid. Further, the mass ratio of the 1,3, 5-tri (4-aminophenyl) benzene, 2, 6-dialdehyde-1, 5-dihydroxynaphthalene, mesitylene and acetic