Inorganic Aerogel Granules Dried at Atmospheric-Pressure

摘要

Silica aerogels using sodium silicates was synthesized by atmospheric-pressure drying. Granulation of silica aerogels was carried out in sequence of hydrogel formation, aging, surface modification, and drying. Rapidly prepared aerogels showed good properties in case aging and surface modification was done within 1 day. Drying is critical to aerogel granulation and the BET area of aerogel dried for a short duration had decreasing with time. It is suggested that sodium silicate-based aerogels granulation could be prepared within less than 5 days, half of initial processing. Aerogel granules had the average diameter of 1 mm and nearly spherical shape. It has very low thermal conductivity of 0.010 W/mK, very light-weight and nanoporous structure with a porosity of upto 95%.