Synthesis of high temperature resistant ZrO2-SiO2 composite aerogels via supercritical fluid deposition

Abstract

A series of ZrO2-SiO2 composite aerogels have been synthesized by adjusting the volume of tetraethoxysilane (TEOS) during supercritical fluid drying process. ZrO2 aerogels have been prepared via the sol-gel reaction using ZrOCl2ꞏ8H2O and the gel initiator malic acid as raw materials. Then the ZrO2-SiO2 composite aerogels have been obtained by supercritical fluid deposition (SCFD). The samples have been characterized applying XRD, FTIR, SEM, TEM, TGA and Nitrogen adsorption-desorption. The introduction of SiO2 can effectively restrain the growth of the nanoparticles and the transformation of crystalline phase, and reduce the linear shrinkage of the aerogels. It indicates the improvement of the thermostability of the ZrO2-SiO2 composite aerogels.