Preparation of hydrophobic silica aerogels by ambitient pressure drying method

Hydrophobic silica alcogels were prepared with tetraethylorthosilicate (TEOS) as precursor, hydrochloric acid and ammonia as catalysts, and trimethylchlorosilane (TMCS) and hexane as a surface modifying agent by drying at ambient pressure. Test methods, such as X-ray diffraction, SEM, BET, FT-IR were adopted to analyze the surface morphology, structure and chemical composition of the samples. The results show that the specific surface area of the resulting SiO2 aerogels is up 900 m2/g. The areogels have a density less than 200 kg/m3, and the hydrophobicity of aerogels is excellent. ©, 2015, Journal of Functional Materials. All right reserved.