Fibrous Sphere Architectures for Efficient Daytime Radiative Cooling and Moisture Management
Dhandayuthapani Thiyagarajan, Shichen Li, Bong‐Kee Lee
Abstract
A radiative cooling nanofabric was designed to reflect incoming solar light, exhibit strong emissivity, and simultaneously provide moisture-wicking properties, making it suitable for personal thermal management in hot outdoor environments. We developed a nanofabric with fibrous sphere architecture, consisting of polyacrylonitrile-SiO 2 and poly(vinylidene fluoride- co -hexafluoropropylene)-TiO 2 -Al 2 O 3 as hydrophilic and hydrophobic layers, complementing high solar reflectivity and directional water transport as well as promising thermal and moisture management capabilities. The fibrous sphere architecture possessed excellent solar reflectivity (93%) and strong emissivity (∼0.95). In outdoor conditions under direct sunlight, the nanofabric was shown to reduce skin temperature by 15 °C compared to the cotton textile. Furthermore, the nanofabric exhibited a subambient radiative cooling capacity of 5 °C at noon and 2 °C at nighttime. This nanofabric architecture provides a promising pathway for the development of radiative cooling nanofabrics with integrated sweat/moisture management, enabling personal cooling technologies and heat control in daily life.