Daytime radiative cooling with silica fiber network
Résumé
Daytime radiative cooling under sunlight can be achieved by embedding micro-sized objects into a binder. In the present article, by carrying out a numerical study of daytime radiative cooling material design using statistical Monte Carlo method, we demonstrate that a silica (SiO2) fiber network can efficiently reflect sunlight via backscattering and efficiently emit infrared thermal radiation. Using a fiber network removes the necessity of the presence of a binder, thus unlike spheres, fibers can be suspended in air. As a consequence, fibers can scatter sunlight efficiently due to the high refractive index difference between air and silica, and efficiently emit thermal radiation due to mitigation of internal reflection losses that arise at the binder air interface. As a result, we show that such a silica fiber network can achieve a net radiative cooling power of 178 W m−2.