SiO2 改性ZrO2 气凝胶高温稳定性

以ZrOCl2·8H2O 为锆源,以环氧丙烷( PO) 为凝胶促进剂制备ZrO2 凝胶,将ZrO2 凝胶置于正硅
酸乙酯乙醇溶液中老化,再结合高温超临界干燥工艺制备了SiO2 改性ZrO2 气凝胶。通过对比ZrO2 气凝胶和
SiO2 改性ZrO2 气凝胶高温结构转变讨论了SiO2 改性对ZrO2 气凝胶高温结构的影响。采用FT-IR、XRD、SEM
和TEM 等分析手段对样品进行高温结构表征。结果表明:采用正硅酸乙酯乙醇溶液老化ZrO2 凝胶后,在ZrO2
凝胶粒子表面形成了一层SiO2 包裹层,这层SiO2 包裹层显著抑制了ZrO2 的扩散、成核和生长过程,高温稳定
性得以显著提高。

High Temperature Stability of ZrO2 Aerogel Modified by SiO2

ZrO2 aerogel modified by SiO2 was synthesized by aging ZrO2 gel prepared using ZrOCl2·8H2O as
precursor, and 1,2-propylene oxide(PO) as a gelation agent in tetraethoxysilane (TEOS) solution followed by high
temperature supercritical fluid drying method ( HTSCFD). The influence of SiO2 to the structure of ZrO2 aerogel at
high temperature was investigated by comparing structural transformation before and after SiO2 modifying. The prepared
samples were characterized using FT-IR spectra, X-ray diffraction ( XRD), scanning electron microscopy
(SEM) and transmission electron microscopy (TEM). The results showed that high temperature stability of ZrO2 aerogel
is highly improved after forming a SiO2 layer covered on the surface of the ZrO2 gel particles during aging process
in TEOS solution.