Multifunctional Aerogel Fiber Radiative Cooling Fabric for Outdoor Personal Thermal Management

Aerogel fibers have many advantages for personal thermal management because of their three-dimensional porous structures, high porosity, thermal insulation, and effective passive daytime radiative cooling (PDRC) capabilities. However, the porous structure of aerogel fibers significantly weakens their mechanical strength, thereby reducing their cooling efficiency. Here, we develop a method for the continuous production of radially gradient porous bacterial cellulose (BC) aerogel fibers (GP-BCAFs) fabrics. The multilevel gradient micro- and nano-porous structures of the GP-BCAFs provide a high solar reflectivity, while the nano-entangled networks and distinctive wrinkled pores improve their mechanical properties by dissipating stress. The designed structure achieves a balance between strong mechanical properties and cooling performance. The GP-BCAF fabrics exhibit a high mechanical and PDRC performance, including a tensile strength of 50 MPa, a solar reflectivity of 94.7%, a mid-infrared (MIR) emissivity of 97.3%, and an outdoor cooling performance with 8.5 °C temperature lower than that of commercial cotton fabrics. Moreover, a self-powered sensor is built using the GP-BCAF fabric, and its electrical signals allow real-time monitoring of human physiological activities. This work provides a universal, sustainable, and scalable approach to producing PDRC aerogel fibers and multifunctional textiles for outdoor personal thermal management.