“Change According to the Situation” – Color-Accommodative Nature-Skin-Derived Thermochromic Membrane for Active All-Season Thermal Management

Abstract

Energy crisis and worsening greenhouse effects cause unprecedented global environmental and economic-sustainability challenges. The emerging all-season thermal regulation technology that can provide comfort to humans without consuming external-energy demonstrates promising prospects. Inspired by the temperature-accommodative skin of the color-changing rain-frog, a biodegradable nature-skin-derived thermochromic membrane (PCTM-H) is nano-engineered for active all-season thermal management using the integrative interfacially wet-casting film-forming and spraying strategy of nature-skin to incorporate polyvinyl alcohol and thermochromic microcapsules. Its outstanding thermochromic origins allow it to switch adaptively between cooling and heating modes without additional energy input. PCTM-H has a light color with high reflectivity in hot summer and a dark-color that absorbs solar radiation in cold winter, with an overall visible light modulation of ≈53.5%, solar modulation of ≈32.2%, and a remarkable emissivity in mid-infrared band (≈86.7%). PCTM-H has exceptional adaptive thermal management capabilities for multitudinous outdoor-applications. Simulation results show that PCTM-H has prominent energy-saving efficiency in cities with different climate zones when utilized as roof-protection membranes. Additionally, the distinguished mechanical features, weatherability, and bio-degradability of PCTM-H substantially increase its potential applications. This study provides a reference for the development of active all-season thermal management materials and high-value utilization of nature-skin, contributing to the goal of carbon-neutrality.