keywords: Physicochemical properties, porosity, silica aerogel, silica, sol-gel
There is an increasing need to preserve the environment in recent times from the global warming perspective. Rice husk when burnt as fuel generates energy and the end product, rice husk ash, which not utilized would result to environmental congestion and pollution; hence the need to find ways to utilize this waste for economic benefits. Silica aerogel was prepared from rice husk ash by sol-gel process. Silica was extracted from the ash as a sodium silicate by boiling it in sodium hydroxide solution. Sodium silicate was neutralized with nitric acid to form silicagel. To prepare aerogel, the pore water of the gel was exchanged with ethanol and then surface modification was done by aging alcogel in ethanol solution. Before drying, ethanol solvent was exchanged with n-heptane. The prepared aerogel was light, crake free solid with bulk density of 0.58𝑔/𝑐𝑚3, porosity of 71.0% and refractive index of 1.122. XRD analysis of the RHA fired at 9000C revealed crystalline structure with particle size of 30.34 nm. The nature of surface modification of the aerogel was studied by Fourier Transform Infrared Spectroscopy (FTIR).
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