Heat-insulating aerogel composites for a hydrothermal reactor

Abstract

The SiO₂–TiO₂ aerogel composites used in the heat insulation of a hydrothermal reactor and the method of their fabrication using a liquid glass technology are analyzed. The process of fabrication of the composite material includes the following stages: the ion exchange of sodium liquid glass with the formation of silica hydrosol; the concentration of hydrosol; the formation of hydrogel and its maturing; the formation of alcogel of an SiO₂–TiO₂ composite material; surface modification; subcritical drying of alcogel with the formation of SiO₂–TiO₂ composite ambigel; and its heat treatment, granulation, and classification. The influence of infrared absorber (titanium dioxide) and the temperature of heat treatment of an SiO₂–TiO₂ aerogel composite material on its structural and thermal characteristics is studied.