Preparation Of Silica Aerogel By Ambient Pressure Drying Process Using Rice Husk Ash As Raw Material

Silica aerogel was prepared from rice husk ash by sol-gel process followed by ambient pressure drying. Silica was extracted from ash as sodium silicate by boiling it in sodium hydroxide solution. Sodium silicate was neutralized with nitric acid to form silica gel. To prepare aerogel, first the pore water of the gel was exchanged by ethanol and then surface modification was done by ageing alcogel in tetraethylorthosilicate solution.