Elastic polybenzimidazole nanofiber aerogel for thermal insulation and high-temperature oil adsorption

Thermal insulation and hot oil adsorption have been paid increasing attention to industrial development. Decomposition and combustion of commercial heat insulation materials may happen in the continuously high temperature (≥ 200 °C) or/and instantaneously ultra-high temperature (≥ 250 °C). Nanofiber aerogel with versatile properties is a potential candidate for thermal insulation and hot oil adsorption. In this work, a novel three-dimensional polybenzimidazole nanofiber aerogel is designed and fabricated for thermal insulation and adsorption of high-temperature oil. Directional freeze casting and freeze-drying techniques are applied to build the three-dimensional structure. A nanofiber-corbelled porous-layer architecture is obtained by optimization with the adhesive effect of starch-derived carbon. Thanks to this architecture, the polybenzimidazole nanofiber aerogel owns suitable mechanical flexibility for delaying heat diffusion. Furthermore, the adsorption and thermal insulation at high temperatures are simultaneously achieved with its high porosity, low thermal conductivity, and thermal stability. This study proposes a promising path for aerogel preparation and applications on effective thermal insulation and hot oil adsorption.