Self-healing inorganic hydrated salt gels for personal thermal management in the static and dynamic modes

Abstract

Thermal comfort is of great significance to maintain the normal metabolism of life. Personal thermal management (PTM) that passively regulates the immediate environment around the human body is a promising alternative. In this work, we report a state-of-the-art concept of self-healing inorganic hydrated salt gels (IHSGs) constructed by ionic crosslinking, covalent crosslinking and hydrogen bond crosslinking for wearable PTM. Sodium sulfate decahydrate (SSD) is selected as the energy storage medium on account of its phase change temperature near the human body temperature. The calcium alginate and the sodium polyacrylate construct the double gel network to anchor the SSD. The dynamic hydrogen bond and the dynamic ionic bond enable the self-healing feature of the SSD IHSGs. The proposed SSD IHSGs with 4% borax, 0.1% sodium hexametaphosphate and 8% sodium polyacrylate demonstrate suppressed phase separation, eliminated supercooling, highly form-stability, high instinct thermal conductivity (0.80 Wm-1K−1), high energy storage capacity (147.14 Jg−1), high self-healing rate (94.3%) and highly cost-effectiveness (energy storage cost 2.44 × 10-3 ¥J−1). Taking advantages of the above merits, the IHSGs are applied in wearable PTM in the static and dynamic modes to meet the thermal comfort requirements. It is anticipated that the one-stop IHSG solution offers great prospect for the advanced wearable PTM.