Intrinsic photothermal phase change materials with enhanced toughness and flexibility for thermal management in extreme environments

Abstract

Polymeric solid–solid phase-change materials (SSPCMs) are capable of reversibly absorbing or releasing high latent heat and have been widely studied for thermal energy storage (TES) due to their excellent shape stability and certain mechanical properties. The photothermal fillers were introduced to impart SSPCMs with photo-responsive ability. However, the incompatibility interface between fillers and SSPCMs matrix always causes serious deterioration of mechanical toughness and flexibility. Herein, we report an intrinsic photothermal SSPCM by incorporating a reactive photothermal agent (dihydroxy naphthalene (DN)) into linear polyurethane SSPCMs. The prepared SSPCMs have adjustable phase transition enthalpy and temperature as well as long-term cycle stability. The highest efficiency of SSPCM in near-infrared photothermal conversion including sensible and latent heat is 59.7 %, and the solar photothermal conversion efficiency is 48.1 %. Moreover, SSPCMs exhibit superior mechanical toughness of 193 MJ/m3 and flexibility, which can withstand repeated rotation, folding and stretching. The SSPCMs developed in this work can enable the human body to obtain the heat needed for life through photothermal conversion in extreme environments such as the Arctic, increasing the probability of survival. Therefore, this study provides a facile strategy for fabricating intrinsic photothermal SSPCMs with high toughness and flexibility properties, which have great potential in wearable device for thermal management in extreme environments.