Cr2O3 doped silicon dioxide aerogel material and preparation method thereof

Abstract

The invention provides a Cr2O3 doped silicon dioxide aerogel material and a preparation method thereof. The preparation method of the Cr2O3 doped silicon dioxide aerogel material comprises the following steps: taking a silicon source as a precursor, adopting an inorganic compound containing the Cr element and an organic compound as doping ions, mixing the compounds with a solvent, a complexing agent and a catalyst to form a composite sol, conducting impregnation technology to be compounded with reinforced fibers, carrying out gelatinizing, ageing, solvent replacement, supercritical carbon dioxide drying, high-temperature pretreatment and other technologies to obtain the product. The preparation method disclosed by the invention is to conduct metal Cr doping and modification on the aerogel through a complexing-gelatinizing method, skillfully combine the complexing reaction with the gelatinizing reaction to increase the complexing force of the metal Cr doping ions in the gel system, effectively restrain the phenomenon that the Cr is not uniform in distribution as the Cr ions are migrated during the follow-up treatment process of the gel, so that the diffusion effect of the complexing-gelatinizing method is uniform and stable, and the complexing-gelatinizing method is better than the in-situ doping method. The aerogel obtained by the complexing-gelatinizing method is treated in advance at high temperature, so as to enable the internal reaction to be conducted thoroughly under high-temperature action, then transform the aerogel to be the Cr2O3 doped stable aerogel structure, and facilitate the pore structure and the heat-insulating property to be stable.

Description

technical field [0001] The present invention relates to a Cr 2 o 3 The invention relates to a doped silicon dioxide airgel material and a preparation method thereof, which belong to the technical field of aerospace heat protection. Background technique [0002] With the continuous advancement of aerospace and aviation technology, various types of aircraft will face various special aerodynamic and thermal environments. Aerodynamic heating is serious during flight. In order to solve the problem of heat protection and heat insulation, a heat protection and heat insulation system needs to be introduced into the structure of the projectile body, shell, hot air channel and engine to protect the normal service of various equipment and materials. At the same time It also needs to meet the requirements of light weight, high temperature resistance, and efficient heat insulation. All kinds of aircraft are on the road of new type, diversification, and speed, and the indicators of lig...

AI Technical Summary

Problems solved by technology

Generally, powder doping and in-situ ion doping are used for doping. The powder doping method is easy to cause problems such as powder agglomeration and uneven distribution. After continuous technical research, in-situ ion doping effectively solves the problems of powder agglomeration. The dispersion uniformity of hetero ions has been greatly improved, but in the study of airgel doping modification, it is found that doped ions are easy to be hydrothermal and solvothermal in subsequent gel treatment due to their ionic radius. Migration of dopant ions occurs during the reaction, resulting in uneven distribution of dopant ions and affecting the thermal insulation stability of the final product

Images