Preparation and Performance Analysis of Hydrophobic Composite Membranes with Modified Nano-silica for Construction Applications

Abstract

In this study, tetraethyl orthosilicate (TEOS) was used as a hydrolysis precursor to prepare nanoscale silica powder and sol through a sol-gel process. Based on the nanosilica (nano-SiO₂) sol, an in-situ modification technique was employed using γ-methacryloxypropyltrimethoxysilane (KH570) and hexadecyltrimethoxysilane (HDTS) as modifiers to obtain modified nano-SiO₂ sol. The modified sol was applied onto glass substrates by manual coating and subsequently cured in a muffle furnace to form a film. The resulting nanocomposite films were characterized by Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), contact angle (CA) measurement, thermogravimetric analysis (TGA), and UV-visible spectroscopy (UV-vis). Analysis of the results indicated that the KH570 and HDTS-modified nano-SiO₂ coatings, due to their large steric hindrance groups, exhibited excellent transparency and hydrophobicity. This modified material shows significant potential for future applications.