Anisotropic porous designed polymer coatings for high-performance passive all-day radiative cooling

Jiliang Zhu; Zhiqiang An; Anxun Zhang; Yike Du; Xuan Zhou; Yizhao Geng; Guifeng Chen

doi:10.1016/j.isci.2022.104126

Anisotropic porous designed polymer coatings for high-performance passive all-day radiative cooling

iScience. 2022 Mar 21;25(4):104126. doi: 10.1016/j.isci.2022.104126. eCollection 2022 Apr 15.

Authors

Jiliang Zhu¹, Zhiqiang An¹, Anxun Zhang¹, Yike Du¹, Xuan Zhou¹, Yizhao Geng¹, Guifeng Chen²

Affiliations

¹ Department of Applied Physics, Hebei University of Technology, Tianjin 300401, P. R. China.
² School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300132, P. R. China.

Abstract

Porous polymer radiative cooling coatings (PPCs) have attracted attention due to their ability of drawing and radiating heat from a hot object into the outer space, without any energy consumption. However, high performance of PPCs has yet to be achieved and the large-scale production of radiative cooling technology is still facing high cost and complex manufacturing constraints. Here, we propose a simple, inexpensive, scalable approach to fabricate anisotropic (P(VdF-HFP))_ap PPCs (TPCs) by dissolution and diffusion between solvent and non-solvent-induced phase separation. By adjusting the porosity, pore size, and geometry, a sub-ambient temperature drop of ∼6.3°C in daytime and 10.1°C in night-time was achieved under a solar reflectance of 0.92 and an atmospheric window emittance of 0.96. A thermoelectric generator with an output voltage of almost zero reached 7 V/m² after coating with TPCs. This could provide a convenient, economical, and environment-friendly way for PPCs materials toward efficient cooling and power generations.

Keywords: Coatings; Energy management; Energy materials; Polymers.