Aramid Nanofiber Hybrid Aerogels for Thermal Management

As lightest artificial solid material, aerogels have broad application prospects in thermal management due to its low density, high porosity, and excellent thermal insulation properties. Self-supporting aramid nanofiber (ANF) hybrid aerogels were designed by two-step induced gelation. Polyamic acid (PAA) was used to induce pregelation following protic acid to achieve full gelation. The ANF hybrid aerogel inherited excellent heat resistance and thermal stability of the aromatic polyamides. ANF hybrid aerogel owned an extremely low density of 0.027 g/cm 3 and a high porosity of 96.84%. Notably, through the designed oriented structures, aerogels exhibited excellent thermal insulation and mechanical performance; the compressive strength of the aerogel was achieved up to an impressive 228.23 kPa, which is highly remarkable among similar lightweight porous materials. Additionally, the material exhibits outstanding thermal camouflage and thermal stability with a decomposition temperature as high as 540 °C. These features rendered the ANF hybrid aerogel with exceptional characteristics to be applied in aerospace, thermal insulation, and energy storage.