Preparation and Characterization of SiO2 Nano Porous Materials by Two-step Approach in Water System

SiO2 nano porous material was prepared by acid-alkali two-step approach with low cost industrial silica sol as a silicon source and deionized water as a solvent. The surfactant was used as the surface modifier to keep the integrity of the sample in the drying process. The SiO2 nano porous material under ambient pressure drying shows low density of 225 mg/cm(3), low thermal conductivity in the range of 0.04-0.07W/m.K. This method greatly reduces the cost in the preparation of SiO2 nano porous material.