Microtexture, Microstructure Evolution and Thermal Insulation Performance of Carbon Aerogels with High-Temperature Treatment

Abstract

The microtexture, microstructure evolution and thermal insulation performance of carbon aerogels subjected to high-temperature treatment were investigated in detail. The results showed that carbon aerogels derived from resorcinol-formaldehyde (RF) resin were composed of fine particles and cavities, which consisted of typical non-graphitized carbon according to X-ray diffraction analysis. The microcrystallite size (La) of the CAs increased from 4.49 nm to 6.92 nm, and the specific surface area (SBET) and the total pore volume (Vtal) decreased from 727 to 290 m2/g and from 0.963 to 0.543 cm3/g, respectively, as the temperature increased from 900 °C to 1800 °C. The micropore-specific surface area and the micropore volume decreased with increasing treatment temperature, and a small amount of macropores (>50 nm) appeared at a temperature of 1500 to 1800 °C. The carbon aerogels retained their porous structure at higher temperature, which indicated that they hold potential for application in the field of thermal insulation in high-temperature environments.