Aramid nanofibrous aerogels and their phase-change composites for highly efficient thermal management

Aerogels, as currently the lightest artificial solid materials, characterized by low thermal conductivity and light weight, high porosity and high specific surface area, had gotten much attention for application of high-performance thermal insulation composites and thermal management materials. In this study, a novel thermal insulation aerogel (APP) consisting of aramid nanofibers (ANF), polyethylene glycol (PEG) and polyimide (PI) was prepared by vacuum impregnation and chemical imidization. The introduction of PI increases the interfacial thermal resistance and reduces the heat transfer rate, which results in a low thermal conductivity (0.04105W/(m/k)). Under the external environment of 200 °C, its internal temperature is only 77.4 °C. The composite aerogel exhibited excellent thermal storage capabilities, achieved a latent heat of 158.9J⋅g −1 . The porous and layered structure of the aerogel endows it low density (0.033 g/cm 3 ), excellent compression strength (583kpa) and fatigue resistance. The bifunctional elastic composite aerogel with thermal storage and insulation properties was prepared, which is an ideal candidate for next-generation thermal management materials for transportation, military and aerospace applications.