Fabrication of novel water glass-based monolithic aerogels with fibrous skeleton under alkaline for oil sorption and thermal evaporation

Abstract

We presented the fabrication of novel water glass-based monolithic aerogel reinforced with the electrospun SiO2 nanofibers (SNFs) by one-step acid catalysis in alkaline condition under ambient pressure drying (APD). Compared with the powder-like water glass-based aerogel (WAG), integrated monolithic aerogel composited with nanofibers (FWAG) was successfully constructed featured with core/shell fibrous skeleton, low density, high porosity, hydrophobic surface and enhanced mechanical property. The obtained FWAG exhibits compressive elastic modulus of 0.13 MPa for FWAG-3 and a sorption capacity of 11.83 g−1 for CH2Cl2, as well as good insulator performance used at high temperature of ∼460 °C without obvious damage. The low density, hydrophobicity and excellent insulation property enable the FWAG to be applied as insulator for solar thermal evaporation with a water evaporation rate of 1.35 kg m−2h−1 and conversion efficiency up to 88.4% at one solar intensity to produce fresh water.