Rapid and microthermal synthesis of centimetre-sized mesoporous silica aerogel sphere by using DMSO-CO2 as solvent

Abstract Centimetre-sized mesoporous silica aerogel sphere (SAS) was synthesized via sol-gel technology by one-step aging/solvent exchange at 2 MPa and using DMSO-CO 2 as solvent. DMSO-CO 2 solvent was obtained at 7.5 MPa with CO 2 fluid in autoclave. The influence of an important factor, temperature, on the SASs’ performance is briefly discussed and the optimal temperature is 4 °C. Low temperature is an effective way to overcome the fragility and shrinkage of SASs. Investigations by bulk density, FTIR, BET and FE-SEM indicate that the SAS has a typical three-dimensional porous structure with pore diameter about 25.4 nm, minimum bulk density 0.12 g/cm 3 and specific surface area as high as 1078 m 2 /g. Due to the good properties of mesoporous, the SAS could be a promising candidate of filling materials.