Asymmetric Wettability in Carbon Nanofiber Aerogels via In Situ Polymerization for Unidirectional Moisture Transport and Dual-Mode Heating

Developing wearable textiles that integrate efficient thermal insulation, active heating, and directional moisture-wicking remains a significant challenge for protection in extreme environments. Herein, we develop a facile, scalable monolithic Janus carbon nanofiber aerogel (PPy@CNFA) via a one-step single-sided in situ polymerization of polypyrrole (PPy) on a three-dimensional (3D) interconnected carbon nanofiber aerogel skeleton. Unlike conventional bilayer Janus materials that are plagued by interfacial delamination, pore clogging, and inherent performance trade-offs, this strategy enables selective deposition of PPy particles on the fiber surface, establishing a continuous wettability gradient along the material thickness direction without disrupting its inherently high-porosity interconnected network. The optimized aerogel carbonized at 1000 ° C exhibits an ultralow thermal conductivity of 28.41 mW m –1 K –1 , serving as a reliable passive thermal barrier against extreme cold/heat environments. Meanwhile, the synergistic light-harvesting capacity and continuous conductive pathways from the graphitized carbon network and PPy particles endow the material with efficient dual-mode active heating performance, reaching steady-state temperatures of 89 ° C under 1 sun illumination and 71 ° C at a safe 5 V driving voltage. Furthermore, the monolithic aerogel simultaneously achieves efficient unidirectional moisture transport for sweat management, excellent compressive resilience, high air permeability, and short-term flame resistance under direct flame exposure without molten dripping. This work provides a facile, scalable platform for the design of multifunctional integrated Janus materials, showing great application potential for next-generation smart protective clothing in extreme environments.