Asymmetric Silk Textile Enabling Dual-Mode Heating for Day-Night Adaptive Passive Personal Warming.

Advanced thermal management textiles are required to deliver efficient warmth across day-night environmental fluctuations and diverse use scenarios. This requires solar absorption for daytime heat gain, together with low mid-infrared emissivity and thermal conductivity for nighttime heat retention; however, integrating these functions into textile remains challenging. Here, this study reports an asymmetric silk textile with an embedded ceramic nanofiber network for orientation-switchable passive personal warming. Natural silk is used as a lightweight and breathable substrate, while polydopamine-assisted MXene assembly enables efficient photothermal conversion. Ag nanowires provide low mid-infrared emissivity to reduce radiative heat dissipation. Meanwhile, porous SiO2 nanofibers are introduced as a thermal decoupling layer to offset the increased thermal conductivity caused by conductive fillers, thereby reconciling low emissivity with low heat conduction. Under 1000 W m-2 solar irradiation, the fabric delivers temperature increases of 30.4°C and 18.2 °C in two heating modes, demonstrating switchable solar heat harvesting. In outdoor nighttime tests, it raises skin temperature by 6°C and 4°C, confirming effective radiative heat retention. Beyond thermal regulation, the fabric possesses hydrophobicity, breathability, UV protection, and EMI shielding, underscoring its multifunctional wearability. This work offers a structural strategy for adaptive passive thermal management textiles operating across day-night environments.