Highly flexible and low-shrinkage polyimide nanofiber aerogels as advanced thermal insulation materials

Polyimide (PI) aerogels, as a representative type of organic aerogel, exhibit low density and high thermal stability; but the rigid structure and high shrinkage rate significantly limit their widespread applications. In this work, PI nanofiber (PINF) aerogels are successfully constructed through a combination of electrospinning and freeze-drying techniques. This innovative approach results in a mechanically robust nanofiber network that enhances the aerogels’ flexibility, compressive resilience, and significantly reduces volumetric shrinkage compared to traditional PI aerogels. Systematic evaluations reveal that the incorporation of nanofibers not only improves dimensional stability but also yields aerogels with high porosity and low density. Notably, the PINF-1.0 exhibits remarkable mechanical properties and a minimal residual strain after cyclic loading, indicating excellent fatigue resistance. Furthermore, PINF aerogels retain good thermal stability and insulation capabilities, emphasizing their potential as advanced materials for flexible thermal insulation solutions in energy-efficient technologies. This research significantly contributes to overcoming the limitations of traditional PI aerogels, paving the way for their broader practical applications.