Polyimide/CsxWO3 composite aerogel fibers with dual-channel thermal management strategy.

Polyimide aerogel fibers (PAFs) have good thermal insulation due to their low density and ultra-high porosity. In this work, in order to further improve the temperature regulation performance of PAFs in extremely cold environments, a novel polyimide/CsxWO3 composite aerogel fiber (PCAF) was prepared by the freeze-spinning technology. The as-prepared PCAFs exhibit lightweight, high-strength and thermal insulation properties. Particularly, the outstanding near-infrared absorption of CsxWO3 could endow the PCAF textiles with excellent photothermal conversion and radiative heating under solar irradiation in cold environments. It was clarified that the photothermal conversion efficiency of the PCAF-8 can be increased by about 3 times compared with the pure PAF after exposure to infrared radiation for 100 s. This result indicates that the PCAFs possess excellent self-heating and photothermal temperature regulation performance, which are significantly different from PAF. The thermal insulation and self-heating of the PCAFs due to their porous structure and photothermal conversion can synergistically keep warm and inhibit human heat loss in the cold, reaching a kind of dual-channel thermal management mode. In addition, the CsxWO3 component with visible light transmission is helpful to maintaining the original color of the fiber, avoiding the dull and unappealing color of conventional photothermal coatings. Therefore, this work provides a new strategy for outdoor personal thermal management in cold weather, making PCAFs a promising solution for extreme weather applications beyond traditional PAFs. [ABSTRACT FROM AUTHOR]