Design and performance comparison of polymer-derived ceramic ambigels and aerogels

Abstract

This work reports the synthesis and characterization of preceramic-and polymer-derived SiOC aerogels obtained from a commercial siloxane resin. The preceramic aerogels were obtained by ambient pressure drying (ambigels) and CO2 supercritical drying. Despite different drying processes, the final ceramic ambi/aerogels have very similar microstructural features in density, porosity, pore size, and specific surface area. Both materials have shown promising results for oil sorption and water cleaning. Supercritically dried-SiOC aerogel had low thermal conductivity with 0.046 W.m(-1).K-1 at RT and 0.073 W.m(-1).K-1 at 500 degrees C. These results suggest that substituting the rather complicated and expensive CO2-SC drying with the more friendly and cheap ambient pressure drying can be done without having to accept significant microstructural/property degradation.