Preparation method of porous silicon carbide nanofiber

Abstract

The invention discloses a preparation method of a porous silicon carbide nanofiber. The preparation method comprises the following steps of: (1) preparing a carbon nanofiber precursor polymer spinning solution; (2) performing electrostatic spinning to prepare a polymer nanofiber; (3) carrying out pre-oxidization crosslinking on the polymer nanofiber; (4) carrying out high-temperature firing on the pre-oxidized polymer nanofiber to prepare a carbon nanofiber; and (5) carrying out carbon thermal reduction on the carbon nanofiber and silicon powder to obtain the porous silicon carbide nanofiber. According to the preparation method, the morphology, the diameter and the ordering of the obtained silicon carbide nanofiber can be effectively regulated and controlled through simple means; the production cycle is relatively short so that expanded production can be conveniently realized and the preparation process is simple so that the industrial production can be conveniently realized; the porous silicon carbide nanofiber has wide application prospect in the fields of high-temperature filtration, high-temperature catalysis, catalyst carriers, heat insulation and sound insulation, gas separation, chemical sensors and the like.

Description

technical field [0001] The invention relates to a method for preparing silicon carbide fibers, in particular to a method for preparing porous silicon carbide nanofibers. Background technique [0002] Porous silicon carbide has the characteristics of large specific surface area, low density, high temperature resistance, corrosion resistance, etc. Wide application prospects. At present, different porous silicon carbide forms, such as bulk, aerogel, nanotube, nanowire, foam ceramics and nano whiskers, have been reported, and there are many methods for preparing porous silicon carbide, such as electrochemical etching, sol-gel glue method, carbothermal reduction method, chemical vapor infiltration and nano casting method, etc. The research on silicon carbide fibers mainly focuses on the preparation of micron-scale high-strength silicon carbide fibers by melt spinning, and there are few related reports on porous silicon carbide fibers, especially nano-scale porous silicon carbid...

AI Technical Summary

Problems solved by technology

CN101876095A discloses a method for preparing silicon carbide fibers. Utilizing the principle of precipitation classification, the electrospinning method can be used to spin very dilute polycarbosilane suspensions, and the obtained polycarbosilane precursors are subjected to non-melting crosslinking treatment and high temperature After firing, porous silicon carbide ultrafine fibers can be obtained, with a fiber diameter of 0.5-2 μm, but the yield of very dilute solution spinning fibers is low, which is not suitable for large-scale preparation

But the average diameter of the same prepared silicon carbide fibers is 0.5 ~ 3 μm, it is difficult to realize the preparation of porous silicon carbide nanofibers; The molecular weight is generally low, the spinnability is poor in the electrospinning process, and the obtained fiber diameter is not uniform

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