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CN-121972027-A - High-permeability nanoscale silicon carbide ceramic flat membrane and preparation method thereof

CN121972027ACN 121972027 ACN121972027 ACN 121972027ACN-121972027-A

Abstract

The application belongs to the technical field of ceramic membranes, and particularly provides a high-permeability nanoscale silicon carbide ceramic flat membrane and a preparation method thereof. A preparation method of a high-permeability nano-grade silicon carbide ceramic flat membrane comprises the following steps of 1) mixing silicon carbide and an auxiliary agent, then adding dispersion sol and deionized water to obtain pug, 2) extruding, secondary aging and extrusion molding after the pug is aged to obtain an original main body, 3) sintering the original main body, dipping a coating liquid to obtain the high-permeability nano-grade silicon carbide ceramic flat membrane, wherein the dispersion sol comprises bacterial cellulose, epoxy silane, polyaspartic acid polymer and polyacrylonitrile dispersion liquid. The high-permeability nano-grade silicon carbide ceramic flat membrane prepared by the application has higher porosity and pure water flux.

Inventors

  • ZHANG YUNFEI
  • HE JINPING
  • QI YUANFENG
  • SHEN HONGMEI
  • GAO QI

Assignees

  • 浙江坚膜科技有限公司

Dates

Publication Date
20260505
Application Date
20260408

Claims (10)

  1. 1. The preparation method of the high-permeability nanoscale silicon carbide ceramic flat membrane is characterized by comprising the following steps of: 1) Mixing silicon carbide and an auxiliary agent, and then adding dispersion sol and deionized water to obtain pug; The dispersion sol is prepared by mixing bacterial cellulose, epoxy silane and polyaspartic acid after reaction, and polyacrylonitrile dispersion liquid and zinc ion aqueous solution; 2) After the pug is aged, extruding, secondary aging and extrusion molding are carried out to obtain an original main body; 3) The original main body is sintered and impregnated with the coating liquid to obtain the high-permeability nano-grade silicon carbide ceramic flat membrane.
  2. 2. The method for preparing the high-permeability nano-scale silicon carbide ceramic flat membrane according to claim 1, wherein the preparation method of the dispersion sol in the step 1) comprises the following steps: S1, mixing bacterial cellulose and deionized water, adding epoxy silane and polyaspartic acid, stirring, adding a catalyst, performing polymerization reaction, and cooling to obtain a base solution; S2, adding polyacrylonitrile powder into a sodium thiocyanate aqueous solution, stirring to obtain a polyacrylonitrile solution, adding deionized water for precipitation, filtering, washing, re-dispersing solid components in the deionized water, and shearing at a high speed to obtain a polyacrylonitrile dispersion; And S3, mixing the base solution with the polyacrylonitrile dispersion liquid, then adding the zinc acetate aqueous solution, and continuously stirring to obtain the dispersion sol.
  3. 3. The method for preparing the high-permeability nano-scale silicon carbide ceramic flat membrane according to claim 2, wherein in the step S1, the mass ratio of the bacterial cellulose to the deionized water to the polyaspartic acid is 1 (200-220) (1.6-2).
  4. 4. The method for preparing a high-permeability nano-scale silicon carbide ceramic flat membrane according to claim 2, wherein in the step S3, the concentration of the zinc acetate aqueous solution is 0.3-0.5mol/L.
  5. 5. The method for preparing the high-permeability nano-grade silicon carbide ceramic flat membrane according to claim 2, wherein in the step 1), the mass portion of silicon carbide is 100-120, the mass portion of auxiliary agent is 8-10, the mass portion of dispersion sol is 2-4, and the mass portion of deionized water is 10-15.
  6. 6. The method for preparing a high-permeability nano-scale silicon carbide ceramic flat membrane according to claim 1, wherein in the step 1), the auxiliary agent comprises kaolin, methylcellulose, boron carbide and alumina.
  7. 7. The method for preparing a high-permeability nano-scale silicon carbide ceramic flat membrane according to claim 1, wherein in the step 2), the aging temperature is 25-30 ℃, and the relative humidity is more than or equal to 85%.
  8. 8. The method of claim 1, wherein the sintering temperature in the step 3) is 1600-1750 ℃.
  9. 9. The method for preparing a high-permeability nano-scale silicon carbide ceramic flat membrane according to claim 1, wherein in the step 3), the composition of the coating liquid comprises silicon carbide, polyethylene glycol and sodium hexametaphosphate.
  10. 10. A high-permeability nano-grade silicon carbide ceramic flat membrane, which is characterized by being prepared by adopting the method as set forth in claims 1-9.

Description

High-permeability nanoscale silicon carbide ceramic flat membrane and preparation method thereof Technical Field The application belongs to the technical field of ceramic membranes, and particularly relates to a high-permeability nanoscale silicon carbide ceramic flat membrane and a preparation method thereof. Background The membrane separation technology is one of core technologies in the field of modern separation science, and ceramic flat membranes are important branches of inorganic membranes, and are widely focused in a plurality of industrial fields by virtue of the characteristics of regular flat plate configuration, excellent mechanical strength, high temperature resistance, chemical corrosion resistance, easy modularization integration and the like. Compared with ceramic membranes with other configurations, the ceramic flat membrane has high filling density and convenient assembly, can effectively improve the separation efficiency, is suitable for different-scale separation scenes, and becomes a key carrier for promoting the large-scale application of the membrane separation technology. Silicon carbide is used as a high-performance inorganic ceramic material, and has excellent chemical inertness, mechanical strength and thermal stability, so that the silicon carbide becomes an ideal raw material for preparing high-performance ceramic flat membranes. By virtue of the advantage of high specific surface area of the silicon carbide particles, a membrane layer structure with uniform pore diameter and good connectivity can be constructed, the permeability and separation efficiency of the membrane are obviously improved, and the requirements of various fields on efficient separation are met. At present, the high-permeability nano silicon carbide ceramic flat membrane has wide application prospects in the fields of environmental protection wastewater treatment, chemical fluid separation, gas purification and the like, but with the continuous improvement of separation requirements, higher requirements are put on the separation performance of the silicon carbide flat membrane, and in the preparation process of the silicon carbide flat membrane, the problem of dispersibility of small-particle silicon carbide is found, so that a series of linkage problems are caused. The silicon carbide particles have large specific surface area and high surface energy, are easy to generate agglomeration phenomenon, are difficult to realize uniform dispersion in a preparation system, lead to uneven pore size distribution and poor connectivity of a membrane layer, directly influence the high flux performance and separation stability of the membrane, and simultaneously restrict the yield and the service life of the membrane material. Thus, it is necessary to prepare a silicon carbide flat sheet membrane with high water flux. Disclosure of Invention Aiming at the problems, the application provides a high-permeability nanoscale silicon carbide ceramic flat membrane and a preparation method thereof, and aims to further solve the problem of silicon carbide dispersion and improve the water flux of the flat membrane. The application firstly provides a preparation method of a high-permeability nanoscale silicon carbide ceramic flat membrane, which comprises the following steps: 1) Mixing silicon carbide and an auxiliary agent, and then adding dispersion sol and deionized water to obtain pug; The dispersion sol is prepared by mixing bacterial cellulose, epoxy silane and polyaspartic acid after reaction, and polyacrylonitrile dispersion liquid and zinc ion aqueous solution; 2) After the pug is aged, extruding, secondary aging and extrusion molding are carried out to obtain an original main body; 3) The original main body is sintered and impregnated with the coating liquid to obtain the high-permeability nano-grade silicon carbide ceramic flat membrane. Further, the preparation method of the dispersion sol in the step 1) comprises the following steps: S1, mixing bacterial cellulose and deionized water, adding epoxy silane and polyaspartic acid, stirring, adding a catalyst, performing polymerization reaction, and cooling to obtain a base solution; S2, adding polyacrylonitrile powder into a sodium thiocyanate aqueous solution, stirring to obtain a polyacrylonitrile solution, adding deionized water for precipitation, filtering, washing, re-dispersing solid components in the deionized water, and shearing at a high speed to obtain a polyacrylonitrile dispersion; And S3, mixing the base solution with the polyacrylonitrile dispersion liquid, then adding the zinc acetate aqueous solution, and continuously stirring to obtain the dispersion sol. In the step S1, the mass ratio of the bacterial cellulose to the deionized water to the polyaspartic acid is 1 (200-220) to 1.6-2. Further, in the step S3, the concentration of the zinc acetate aqueous solution is 0.3-0.5mol/L. Further, in the step 1), the silicon carbide is 100-120 parts by weight, the aux