All-Weather Adaptable Non-Woven Janus Graphene Fibers with Asymmetric Wettability, Reliable Flame Retardancy and Synergistic Evaporative Cooling-Ultrafast Joule Heating

Against the backdrop of drastic global climatic change, personal thermal management (PTM) textiles have emerged as a critical safeguard for human comfort and safety. However, the inherent trade-off between moisture management and active heating functionality significantly impedes their widespread application. Herein, a flexible Janus graphene fiber fabric (J-GFF) was fabricated via wet spinning, selective filtration, Ca²⁺-induced fiber fusion, and floating polymer modification strategies. By tailoring the interfacial fusion degree and surface treatment, J-GFF exhibited an excellent water vapor transmission (WVT) rate of 233.5 g m⁻² h⁻¹ and superior evaporative cooling performance, benefiting from the formed hierarchical structures and adjusted wetting behavior. Thus, when the J-GFF was used as artificial wearable textiles, the temperature of the human skin surface decreased by 4.5°C under normal conditions, and even up to 14°C under heavy perspiration. Moreover, the produced fabric demonstrated extraordinary heating efficiency and flame retardancy, where fabrics could be heated to 175°C at a high heating rate of 690°C s⁻¹ to withstand ∼500°C firing for over 15 s. Thus, this work offers a novel avenue for developing next-generation all-weather and multifunctional PTM textiles with evaporative cooling, breathability, mechanical durability, and Joule heating and safety.