Advanced Bioinspired Personal Thermoregulation Textiles for Outdoor Radiative Cooling.

Abstract

Radiative cooling textiles designed to reflect incoming sunlight and enhance mid-infrared (MIR) emissivity show great potential for ensuring personal thermal comfort. Thus, these textiles are gaining prominence as a means of combating the heat stress induced by global warming. Nonetheless, integrating radiative cooling effects into scalable textile materials for personal thermoregulation remains a formidable challenge. To achieve optimal cooling performance, textiles must exhibit finely tuned optical properties and spectral selectivity. In this study, a radiative cooling smart textile was devised by drawing inspiration from the structure of greater flamingo (Phoenicopterus roseus) feathers, which have effective thermoregulatory properties. Specifically, a nanoporous nonwoven material was fabricated from polyacrylonitrile and alumina particles and integrated with a cellulosic cotton knit fabric through an efficient electrospinning and hot pressing process to produce smart textile metafabric (PAC@T) with superior optical properties and wearer comfort. PAC@T exhibited an average fiber diameter of 501.6 nm and pore size of 857.6 nm, resulting in a solar reflectance of 95 ± 1.2% and an MIR emissivity of 91.8 ± 0.98%. It also demonstrated an enhanced water vapor transmission rate (5.5 kg/m²/24 h), water vapor evaporation rate (334 ± 2.2 mg/h), and significant radiative cooling performance, leading to temperatures 6.1 °C cooler than those achieved by a traditional knitted textile. Thus, PAC@T offers several distinct advantages, namely superior cooling efficiency, long-term durability, and energy-free operation. In addition, it is formed from accessible raw materials via a potentially scalable process that is likely to have substantial applications in industrial generation of smart textiles for personal thermoregulation.