Study on Silica Aerogel Modified by Trimethylchlorosilane

Abstract The mechanical properties of SiO 2 aerogel prepared under atmospheric pressure are poor, so it is difficult to prepare large pieces of materials for practical engineering. In this paper, trimethylchlorosilane (TMCS) was used as a surface modifier to transform hydrophilic substances with higher surface activity into hydrophobic groups, to improve the network strength of SiO 2 aerogel. Super-hydrophobic SiO 2 aerogel was prepared by the sol-gel method under atmospheric pressure. The effects of trimethylchlorosilane on the structure and properties of SiO 2 aerogel were characterized by a specific surface area analyzer, Fourier transform infrared spectrometer, thermal conductivity meter, static contact angle meter, and scanning electron microscope. The results show that the SiO 2 aerogel prepared when n (Si):n (TMCS) is 1 has the best performance. Its density is as low as 0.0759 g/cm 3 , the porosity is as high as 96.5%, the specific surface area is as high as 723.08 m 2 /g, and the contact angle is 163.8°. It has good hydrophobic properties.