High-performance radiative/evaporative thermal regulation using a self-water-recovery thermochromic film

Abstract

Passive radiative cooling has garnered attention as a promising cooling strategy due to its low energy consumption, minimal carbon emissions, and cost-effectiveness. However, passive cooling methods face challenges arising from the limited cooling capacity of thermal radiation. Recent research efforts have focused on integrating evaporative cooling techniques to maximize the cooling potential. Nonetheless, this approach can inadvertently result in undesired cooling effects during cold weather conditions. In this study, we propose a thermal regulator that utilizes a thermochromic material-impregnated hydrogel. The hydrogel maintains transparency below the transition temperature and becomes opaque above the transition temperature. Additionally, the hydrogel exhibits the ability to adsorb moisture from the atmosphere, facilitating continuous evaporative cooling. By leveraging this combined mechanism, our proposed approach demonstrates significant potential for practical applications in the field of thermal regulation.