Rapid synthesis of silica aerogels by microwave irradiation

Silica aerogels prepared via microwave irradiation using tetraethyl orthosilicate (TEOS) as the precursor are described. The aerogels were obtained after subjecting the entire process under microwave irradiation, significantly reducing the synthesis time to 90 min, which is much shorter than the supercritical CO₂ drying (SCD) method and ambient drying (APD) method. The obtained aerogels under microwave irradiation condition with different power and time exhibit surface areas of 831 m² g⁻¹, average pore sizes of 8.67–12.7 nm, and contact angles of 146.5°. The aerogels are thermally stable and the thermal conductivity is relatively low at 0.028 W m⁻¹ K⁻¹, when the molar ratio of E value (EtOH /TEOS) is 8. The results demonstrate the efficiency of synthesizing silica aerogels via microwave irradiation in the industry.