Preparation method of aluminum oxide-silicon oxide aerogel composite material

Abstract

The invention belongs to the field of thermal insulation materials, and discloses a preparation method of an aluminum oxide-silicon oxide aerogel composite material, wherein after preparing silicon dioxide gel is prepared, the surface of the silicon dioxide gel is continuously impregnated with an aluminum sol mixed solution, and compounding is carried out by using a method of coating the silicon dioxide aerogel with aluminum oxide aerogel; Si-OH and Si-OR bonds (wherein R is alkyl) on the surface of the silicon dioxide gel can react with -Al-O- bonds to form a silicon and aluminum aerogel composite network structure, a silicon dioxide aerogel network framework can play a role in supporting an aluminum oxide aerogel framework, the situation that the aluminum oxide aerogel structure collapses at the high temperature at present is reduced, and meanwhile, the aluminum oxide aerogel skeleton also improves the mechanical property of the silicon dioxide aerogel. Besides, the aluminum oxide aerogel is arranged on the outermost layer of the composite gel, approximately forms a gradient structure and can well protect the silicon dioxide aerogel network structure at high temperature, and the aluminum oxide aerogel and the silicon dioxide aerogel cooperate with each other to jointly improve the heat insulation and mechanical properties of the composite material.

Description

technical field [0001] The invention belongs to the field of thermal insulation materials, and in particular relates to a preparation method of an alumina-silicon oxide airgel composite material. Background technique [0002] As the flight speed of the aircraft is getting faster and the surface temperature is getting higher and higher, the thermal insulation effect and mechanical properties of conventional aluminum silicate or mullite fibers can no longer meet the thermal protection requirements of aerospace vehicles in the high temperature section. The use of nano-airgel thermal insulation composites has become the leading direction for efficient thermal insulation. [0003] Airgel is currently the most ideal lightweight thermal insulation material. It is a lightweight, amorphous and porous solid material composed of nano colloidal particles or polymer molecules. It has extremely low density, high specific surface area and high porosity. . The pore size of airgel (<50n...

AI Technical Summary

Problems solved by technology

However, the inherent low strength, high brittleness, poor ability to block infrared radiation, and difficulty in forming of alumina-silica airgel materials limit the application of alumina-silica airgel in industry.