Reversible Water Transportation Diode: Temperature‐Adaptive Smart Janus Textile for Moisture/Thermal Management

“Air‐conditioning” textiles with thermal‐ or moisture‐managing functions are of high interest for not only improving human comfort but also reducing energy consumption. However, making the textile sensitive to the surrounding environment and exhibit adaptive thermal/moisture management still remains a great challenge. Herein, a double‐sided synergetic Janus textile is developed, featuring reversible diode‐like water transportation and adjustable thermal convection upon temperature change. The incorporated responsive polymer networks with inverse transitions on the opposite sides provide synergistic surface energy gradients and capillary gradients that generate drying and cooling effects (with 50% faster water evaporation and 1.2–2.3 °C cooler than with cotton fabric) in hot weather while offering thermal preservation (120 s longer needed to be cooled down and maximumly 3.3 °C warmer than with cotton fabric) in a cold environment. This method could provide ideas for the development of more adaptive textiles and clothing to address maximum personal comfort in demanding situations. A double‐sided synergetic Janus textile that features moisture/thermal management has been developed. Its temperature‐adaptive reversible wettability gradient and pore size change give rise to smart regulation of the microclimate near the skin: dissipating moisture/heat in hot weather while weakening undesired heat loss in cold environments. This study may open the gate for designing smart textiles addressing self‐adaptive personal comfort.