Colorful and temperature-adaptive radiative coolers for all-season thermal management applications

Abstract

The cooling effect, caused by the sustainable radiative cooling, might be an adverse factor for a cause thermal management system during cold hours. To address this issue, a self-adaptive radiative cooler (SARC), integrating thermochromic microcapsule (TCM) and silica aerogel (SA) in porous polymer substrate, was designed and fabricated for dynamic thermal management system. SARC can adaptively change its solar reflectance according to the external temperature, thereby, achieving dynamic radiative cooling regulation. When the external temperature exceeding the transition temperature, SARC will experience an apparent color change (from black/red/yellow/blue to white), indicating its capacity (ΔR<inf>sol</inf>∼30 %) in dynamic manipulation of solar reflection. The incorporation of SA significantly increases the infrared emittance. The prepared SARC exhibited excellent elective infrared emissivity (0.922 in the atmospheric window), promoting the heat dissipation via radiation. The field test shows that SARC exhibiting excellent solar heating effect under solar radiation when the ambient temperature lower than the transition temperature. SARC shows similar radiative cooling performance to the porous TPU when the temperature exceeds the transition temperature. This study provided a facile approach to prepared radiative cooler with temperature-responsive solar reflectance.