Three TMCS Hydrophobic Modification Methods of New Building Insulation Material SiO_2 Aerogels

摘要

Trimethylchlorosilane as a modifier and tetraethoxysilane, an acid catalyst, as raw material were modified hydrophobically through the copolymerization, surface derivative, and hierarchical hydrophobic modification methods. The modified material was prepared as hydrophobic SiO_2 aerogels by constant pressure drying. Finally, thermal stability, pore structure, and chemical composition of SiO_2 aerogels were analyzed using TG-DSC, FTIR, and BET. The results show that the hydrophobic property of SiO_2 aerogels prepared using hierarchical hydrophobic modification and surface derivative methods have excelled characteristics, such as super-hydrophobicity. The aerogels prepared through the two different methods have a mesopore structure with mesopores of 2–70 nm; However, they have no micropore structure.