Hydrophobic, Pore‐Tunable Polyimide/Polyvinylidene Fluoride Composite Aerogels for Effective Airborne Particle Filtration

Abstract

Abstract Polyimide (PI) aerogels have great potential as filter materials, owing to their unique porous structure and excellent thermodynamic properties. In this work, polyvinylidene fluoride (PVDF) is introduced into the 3D network structure of crosslinked PI by phase separation to prepare PI/PVDF hybrid aerogels. By adding different amounts of PVDF, effective control of the aerogel porous structure is achieved, as a result, the air permeability of the hybrid aerogel is significantly improved while still achieving a filtration efficiency of airborne particulates of more than 99.8%. PVDF is aggregated and dispersed on the surface or inside of the aerogel in the form of nanoparticles, which effectively increases the hydrophobicity of the material. The contact angle of the prepared PI hybrid aerogel is ≈150°, and the water absorption is as low as 2.2%, which enables the aerogel to maintain structural stability in humid environments. In addition, the aerogel exhibits good adsorption effects on organic solvents.