A Janus Textile with Tunable Heating Modes toward Precise Personal Thermal Management in Cold Conditions.

Passive heating textiles (PHTs) have drawn increasing attention due to the advantages of energy-conservation heating. However, the heating capabilities of current PHTs are typically static and non-tunable, presenting poor adaptation to dynamic winter. Herein, a novel Janus textile with tunable heating modes is developed by constructing a customized structure with asymmetric optical properties. This Janus textile is created by coating one side of a cotton fabric with silver nanowires (AgNWs) and then applying transition metal carbides/nitrides (MXene) to the other side. The MXene side exhibits high solar absorptivity and low mid-infrared emissivity, while the AgNWs side has moderate solar absorptivity and mid-infrared emissivity. This structure ensures that the solar and radiative heating temperatures of the MXene side are 16 °C and 1.7 °C higher than those of the AgNWs side. This distinction allows for on-demand, accurate adjustments in solar and radiative heating capabilities by flipping the textile according to ambient temperature. Furthermore, this innovative design also features desired electric heating, thermal camouflage, self-cleaning and antibacterial properties, electromagnetic interference shielding, durability, and wearability. The Janus textile enables precise thermoregulation of the human body to adapt to variable cold weather, making it essential for optimal personal thermal management and climate change mitigation.