The Effect of Aging Temperature and pH Value of Aging Solution on the Microstructure of ZrO₂-SiO₂ Aerogels

Abstract

ZrO2-SiO2 gels were prepared by prehydrolysis method with sol-gel process. Then,the wet gels were aged at different temperatures (60,110,170 °C) in ethanol or alkaline solution (pH=8). Finally, the monolithic ZrO2-SiO2 aerogels were obtained by supercritical fluid drying. N2 adsorption-desorption, scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FT-IR) were used to characterize the microstructure of aerogels. The aim of this research is to study the effect of aging temperature and pH value of aging solution on the microstructure of ZrO2-SiO2 aerogels. The results show that the specific surface area and pore volume of ZrO2-SiO2 aerogels aging in alkaline solution (pH=8) is lower than that of aging in the ethanol. And there is a shift of the pore size distribution towards larger values. This is because the cross-linking reaction in alkaline solution enlarges the particle size. As the aging temperature increases, the specific surface area and pore volume decrease and the particle size distribution of ZrO2-SiO2 aerogels is more uniform.

SiBCN-ZrO2 hybrid ceramic aerogels through the polymer-derived ceramics (PDCs) route

“…So it could be a potential aerogel matrix for high temperature applications. Zirconium dioxide (ZrO 2 ) is a kind of material with excellent chemical stability, thermal stability, insulativity and light-proofness, besides that, ZrO 2 still has an outstanding ion exchange performance which could be used in catalysts, adsorbents and other applications [28][29][30][31]. Therefore, SiBCN-ZrO 2 aerogel not only holds the ion exchange capacity which comes from ZrO 2 , but also retains the high thermal stability and good mechanical properties of SiBCN, showing a great potential in these applications such as insulation, adsorption and catalytic.…”