Ultralow density silica aerogels were formulated by sol-gel process using tetramethyl orthosilicate as the precursor. A supercritical drying step was performed using acetonitrile solvent extraction. These aerogels were found to have a high specific surface area (~812m2/g) and they were found to be excellent thermal insulators with thermal conductivities ranging from 0.024 to 0.043 W/m K at temperatures up to 400oC....
In this study, ultralow density silica aerogels were synthesized and their thermal conductivities were tested to determine how supercritical drying affected the samples. A thermal analyzer measured the thermal conductivity of the silica aerogels using the transient plane source (TPS) method which determined that the thermal conductivity of silica aerogels increased with temperature....