Energy-saving cooling materials with strong operability are desirable towards sustainable thermal management. Inspired by the cooperative thermo-optical effect in fur of polar bear, we develop a flexible and reusable cooling skin via laminating a polydimethylsiloxane film with a highly-scattering polyethylene aerogel. Owing to its high porosity of 97.9% and tailored pore size of 3.8 +- 1.4 micrometers, superior solar reflectance of 0.96 and high transparency to irradiated thermal energy of 0.8 can be achieved at a thickness of 2.7 mm. Combined with low thermal conductivity of 0.032 W/m/K of the aerogel, the cooling skin exerts midday sub-ambient temperature drops of 5-6 degrees in a metropolitan environment, with an estimated limit of 14 degrees under ideal service conditions. We envision that this generalized bilayer approach will construct a bridge from night-time to daytime radiative cooling and pave the way for economical, scalable, flexible and reusable cooling materials.
@article{arxiv.2005.09177,
title = {Generalized bioinspired approach to a daytime radiative cooling "skin"},
author = {Meng Yang and Weizhi Zou and Jing Guo and Zhenchao Qian and Heng Luo and Shijia Yang and Ning Zhao and Lorenzo Pattelli and Jian Xu and Diederik S. Wiersma},
journal= {arXiv preprint arXiv:2005.09177},
year = {2020}
}
Comments
15 pages, 4 figures, of which another version has been accepted by ACS ami but not published yet