Preparation of compressible silica aerogel reinforced by bacterial cellulose using tetraethylorthosilicate and methyltrimethoxylsilane co-precursor

Silica aerogel is one of the most attractive insulation materials but has not been broadly applied yet because of limitation of its fragile nature. In this work, we synthesized a compressible bacterial cellulose/silica aerogel composite from the co-precursor of tetraethylorthosilicate and methyltrimethoxylsilane by a two-step acid-base catalyzed sol-gel method followed by supercritical CO₂ drying. This aerogel composite possessed a series of excellent properties: standing the considerable strain, high resilience, dust-free, low density of 0.066 g/cm³ and low thermal conductivity of 0.0292 W/(m·K) along with hydrophobicity with a water contact angle of 147°. Weight loss analysis indicated that the thermal stability of the as-prepared composites was about 270 °C which primarily depended on the thermal stability of the bacterial cellulose. These outstanding properties were attributed to the Interpenetration Polymer Network structure formed via the co-precursors and the bacterial cellulose and the excellent fabric of the aerogel retained by the supercritical CO₂ drying. The results suggest that the as-prepared aerogel composite has potential applications as a suitable insulation material with dust-free and resilience.