The laborious supercritical CO2 drying method limits the commercial availability of polymeric aerogels. Here we demonstrate a green and scalable method for the preparation of high-performance polyimide (PI) aerogels using low-boiling-point solvent mixture of tetrahydrofuran/methanol, and especially using sublimation drying instead of supercritical CO2 drying. Monolithic and powdery PI aerogels with nanofibrous morphology, low density and high thermal stability can be prepared facilely and thus facilitate their applications in many fields, especially high-temperature resistance, which are of essential importance.
