Effect of thermal treatment process on the structure of C/SiO₂composite aerogels

Carbon/silica composite (C/SiO2) aerogels were synthesized by using tetraethyl orthosilicate, 3-aminopropyltriethoxysilane, trimethylchlorosilane, resorcinol as the silicon and carbon sources, and ethanol as solvent, via the sol-gel process followed by supercritical ethanol drying and thermal treatment. The influence of thermal treatment process on the structure of C/SiO2 composite aerogels was analyzed mainly and measured by Fourier transform infrared spectrometer, X-ray diffraction and nitrogen adsorption-desorption analysis. The results showed that the optimum thermal treatment temperature of C/SiO2 composite aerogels was 1,300°C. With the increase in the thermal treatment time, the linear shrinkage of the composite aerogels increased gradually, and the pore volume, average pore diameter and specific surface area of the composite aerogels increased first and then decreased.