Self-healing sodium acetate trihydrate phase change material gel demonstrating solar energy conversion and storage for personal thermal management under static and dynamic modes

The medium temperature phase change material gels (PCMGs) have a thermal storage capacity to meet the body's needs for thermal comfort in cold environments. However, traditional PCMGs are prone to leakage and break in solid-liquid phase change process towards personal thermal management (PTM) application. This study develops an innovative approach that uses covalent and ionic crosslinking to simultaneously maintain the form-stability and self-healing capabilities of sodium acetate trihydrate (SAT) PCMGs. The self-healing performance of SAT PCMGs is contributed to the dynamic interaction of ionic bonds and hydrogen bonds in sodium polyacrylate (PAAS) and calcium alginate (CA). The interaction between SAT and dual network (PAAS and CA) provides form-stability to SAT. To remove SAT's supercooling degree, sodium dihydrogen phosphate dihydrate is chosen as the nucleating agent. The proposed SAT PCMGs demonstrate high shape stability, high self-healing properties, high thermal conductivity (0.58 W m−1 K−1) and high thermal energy storage capacity (170.30 Jg-1). Germanium (Ge) membrane prepared by combining Ge powder with chitosan presents high solar absorption. A device consisting of Ge membrane and SAT PCMG is applied in static and dynamic PTM to produce thermal comfort by solar-thermal conversion, thermal energy storage and thermal energy utilization. With this effort, an advanced substitute for the upcoming solar-thermal PTM devices is created.