Moisture-wicking fabric for radiation cooling

Prolonged exposure to hot weather and direct sunlight can lead to heat exhaustion and skin irritation, which reduces the productivity of outdoor workers and increases health risks. This study has developed a polylactic acid/boron nitride nanosheet composite fabric by electrospinning. Being selectively modified for hydrophilicity, the fabric has combined passive radiative cooling, thermal conductivity and directional sweat wicking to improve thermal comfort in outdoor environments. Compared to conventional cotton fabrics, the composite fibric exhibits excellent solar reflectance (96%) and infrared heat emissivity (93%), along with high thermal conductivity (0.38 W·m^-1 K^-1). In outdoor experiments, the composite fabric lowers skin temperature by 2.0 °C under direct sunlight during the day and by 3.8 °C at night relative to bare skin. The composite fabric features a directional perspiration function and an impressive sweat evaporation rate of 1.67 g·h⁻¹, which can efficiently transport sweat and heat to the fiber membrane surface to keep the skin dry and cool. This work should advance human thermal management strategies for high-temperature outdoor environments.