Study on Preparation of Mesoporous Silica Aerogels with Low Density and High Properties via Ambient Pressure Drying

Abstract

The SiO2 aerogels of low density was fabricated by ion exchange and sol-gel method on the basis of sodium silicate. The effect of pH, aging，addition of DCCA and annealed temperature on the gel time, aerogel density, porosity and the micro-structure was systemly studied. The results showed that when the pH is 5, aging was 30%Vol .of TEOS/ethanol solution ,the addition of DCCA was 1.5ml, the gel system was annealed at 50 for 84 h, 60 for 72h, the best quality of silica aerogels with low density (0.14g/cm3), higher specific surface(610.643 m2/g) and pore size of 20~40 nm can be obtained.