A facile pathway for the incorporation of silica into cellulose aerogels with increased optical transmittance

Silica/cellulose composite aerogels with increased optical transmittance were prepared by incorporation of silica in the matrix, and the obtained aerogels had increased homogeneous microstructure, high porosity and surface area, low density. It indicated that the incorporated silica had an obvious influence on the microstructure of the composite aerogels, the composite aerogels with small content of silica had transmittance about 66% at 550 nm, while for pure cellulose aerogels it was about 44%. Moreover, the composite aerogels had low thermal conductivity (0.04–0.05 W/m k) at ambient conditions. The developed method for the preparation of the cellulose-based aerogels with improved thermal stability, mechanical properties and transmittance, as well as ultralow thermal conductivity made the aerogels as promising candidates for transparent insulators.