Mechanically strong and thermal insulating polyimide/SiO2 aerogel prepared by ambient drying

Ambient drying of polyimide (PI) aerogel is rarely reported due to the strong cross-linking network leading to large shrinkage. In this work, the hydrophobic SiO2 nanoparticles are used as skeleton enhancers and shrinkage inhibitors to maintain the nano-porous network structure and achieve ambient drying of PI/SiO2 aerogels. The results show that the PI/SiO2 aerogel prepared by ambient drying has similar thermal insulation and mechanical properties as the PI aerogel prepared by supercritical drying. The PI/SiO2 aerogel prepared by ambient drying is low-cost and simple to operate, which is expected to realize the industrialization and wide engineering application.