Ordinary pressure preparation method for aluminium oxide composite aerogel rapped by silicon dioxide

Abstract

The invention discloses an ordinary pressure preparation method for aluminium oxide composite aerogel wrapped by silicon dioxide. According to the method, cheap inorganic aluminium salt is taken as araw material, aluminium oxide wet gel is prepared through a collosol-gel method, a framework of the wet gel is wrapped by a silicon dioxide layer, and the effects of surface modification and anti-sintering at the high temperature are achieved; then the aluminium oxide composite aerogel wrapped by the silicon dioxide is obtained through steps of hydrophobic modification and normal-pressure drying.The prepared composite aerogel has the advantages of being lower in density, capable of resisting high temperature and high in temperature preservation performance and can be widely applied to the fields of aerospace, industrial furnaces and the like which need heat insulation under the high temperature condition.

Description

technical field [0001] The invention belongs to the technical field of preparation of inorganic materials, and in particular relates to a normal-pressure preparation method of silica-coated alumina composite airgel. Background technique [0002] Energy saving has been paid more and more attention by the governments of various countries. Among them, the research and application of thermal insulation materials is one of the main measures for energy saving. Effectively prevent the temperature transfer between the surface and the substrate with near-zero energy consumption, and realize thermal protection in an environment where space and overall quality are strictly limited, which is of great significance to promote the development of aerospace, national defense, construction and other industries. [0003] The construction industry and aerospace and other fields all need thermal insulation materials with high temperature resistance, light weight, high strength and excellent perf...

AI Technical Summary

Problems solved by technology

Traditional silica airgel has good thermal insulation performance at low temperatures, but its internal structure will be damaged if used in a high temperature environment for a long time, which will greatly reduce the thermal insulation effect of the material and limit its use in high temperature environments. At the same time, the use of supercritical drying methods to dry wet gels also has disadvantages such as low safety factor and harsh conditions, which limit the industrialization and large-scale application of airgel materials

Due to its high temperature resistance and high strength, alumina is often used in high temperature fields, but it also has defects such as high thermal conductivity and high density.

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