常压干燥合成水玻璃基SiO_2气凝胶

以水玻璃和双氧水为原料一步合成二氧化硅湿凝胶,经老化、溶剂置换及三甲基氯硅烷修饰后,并于常压干燥后获得二氧化硅气凝胶。样品经低温N_2吸附-脱附、红外光谱和扫描电镜测试表明所得二氧化硅气凝胶具有三维多孔结构,且其比表面积可达482 m~2·g~(-1)、平均孔径为24.9nm及表观密度为0.12g·cm~(-3)。

Green and facile synthesis of water-glass-based silica aerogels by ambient pressure drying

The silica aerogel is manufactured via sol-gel method using the eco-friendly hydrogen peroxide and low-cost water-glass as reactants to generate the silica hydrogel in one step without adding extra agents for tuning pH value. For keeping the nanostructure of silica aerogel among drying stage under ambient pressure conditions, the wet silica gel is modified with trimethylchlorosilane to avoid the condensation reaction between Si-OH groups. Finally, the silica aerogel has been obtained after drying at the ambient pressure. The synthesized silica aerogel has been characterized by apparent bulk density, FT-IR, N_2 adsorption/desorption and SEM techniques. And the results indicate that the as-prepared silica aerogel has a typical three-dimensional porous nanostructure with about 24.9 nm of average pore diameter, 0.12 g·cm~(-3) of apparent bulk density and 482 m~2·g~(-1) of specific surface area.