Transparent, robust, and machinable hybrid silica aerogel with a “rigid-flexible” combined structure for thermal insulation, oil/water separation, and self-cleaning

Silica aerogel has many attractive properties, but poor mechanical properties severely limit its practical applications. Many reinforcement strategies have been implemented, however, most of which usually impair other properties of aerogel. Herein, we report a hybrid silica aerogel with excellent comprehensive performance using methyltriethoxysilane (MTES) and multi-alkoxy polyhedral oligomeric silsesquioxane (POSS) with a “rigid-flexible” combined structure as co-precursors by ambient pressure drying. The resulting hybrid aerogel has high strength (compressive strength of 16.25 MPa), low density (0.23 g·cm−3), uniform mesopores (10–30 nm), high specific surface area (815 m2·g−1), low thermal conductivity(28.6 mW·m−1·k−1), good thermal stability (>470 °C), high transparency (>80%) and superhydrophobicity (water contact angle of 152°) with excellent oil/water separation capability and self-cleaning properties. Moreover, the hybrid aerogel shows superb compressive resilience (up to 70% strain) and exceptional fatigue resistance (at the strain of 40% for 30 times). Benefiting from outstanding mechanical properties, the hybrid aerogel is machinable and can be cut into various shapes with a knife. The multifunctional hybrid aerogel holds great promise for the practical applications of transparent energy-saving building, thermal insulation, and oil/water separation.