Method for preparing silicon-boron-carbon-nitrogen porous ceramic with nano pore structure

Abstract

The invention relates to a method for preparing silicon-boron-carbon-nitrogen porous ceramic with a nano pore structure. The method comprises the following steps: uniformly mixing boron trichloride, aniline and simethicone according to a ratio of 1:1:2.5, and heating to react to prepare an organic precursor; then dipping nano polyacrylonitrile fibers in the organic precursor and performing heat preservation at a certain temperature; finally sintering the mixture in a high-purity nitrogen atmosphere, and cooling the mixture to room temperature with the furnace after the heat preservation is finished, wherein after the high temperature nitrogen treatment, the nano polyacrylonitrile fibers are corroded to form silicon-boron-carbon-nitrogen (Si-B-C-N) porous ceramic with the nano pore structure. The aperture of the obtained silicon-boron-carbon-nitrogen (Si-B-C-N) porous ceramic is 150-300 nm, the porosity is up to 78-90%, the silicon-boron-carbon-nitrogen (Si-B-C-N) porous ceramic is high temperature resistant, oxidation resistant, free of obvious oxidation at 950 DEG C in an air atmosphere, and free of obvious loss of mechanical property at 1100 DEG C. The silicon-boron-carbon-nitrogen (Si-B-C-N) porous ceramic can be applied to a diesel exhaust particulate filter (DPF) carrier.

Description

technical field [0001] The invention relates to a method for preparing a composite ceramic material, in particular to a method for preparing a nanoporous silicon-boron-carbon-nitrogen porous ceramic. Background technique [0002] As the environment and ecological pollution become more and more serious, the phenomenon of urban smog is also becoming more and more serious, seriously affecting people's life and health, and the problem of air purification has aroused widespread concern in the society. As a good filter carrier, porous ceramics play an important role in air purification and filtration in various industries. The preparation methods of porous ceramics commonly used today include: organic foam impregnation method, foaming method, template synthesis method, etc. The organic foam impregnation method is to use a porous carrier (such as foam plastic) to absorb ceramic slurry, and then burn out the carrier material at high temperature to form a pore structure. , and the ...

AI Technical Summary

Problems solved by technology

Although the porous ceramics prepared by the foaming method can have complex shapes and porous states of different structures, their porosity is low (generally no more than 50%)

The template synthesis method is to use the pore structure contained in the template, inject the ceramic precursor into the template, and sinter, so that the original pore structure is preserved to prepare porous ceramics with the same structure and shape as the template, but different templates. The mechanical properties of porous ceramics vary greatly and are seriously affected by the type of template.