Preparation of Polystyrene/SiO₂ Composite Aerogel Microspheres

Silica aerogel microspheres demonstrate tremendous potential as fillers for diverse materials across various fields. Enhancing the strength of silica aerogel microspheres is therefore crucial for their practical applications. This study aims to develop novel hydrophobic polymer-reinforced silica aerogel microspheres using water glass as the precursor, hexamethyldisilazane (HMDS) as the modifier, and styrene as the crosslinking agent, with further strength enhancement achieved through short-term thermal post-treatment. The effects of varying polystyrene coating levels, crosslinker dosage, and short-term heat treatment on the structure and properties of silica aerogel were investigated. The optimized silica aerogel microspheres (Sample A-6) exhibited a specific surface area of 604.8 m²/g and a thermal conductivity of 0.030 W·m^-1·K^-1 and demonstrated excellent hydrophobicity and mechanical stability.