Thermal-Conductive, Dynamic Cross-Linked Solid–Solid Phase Change Composites toward Sustainable Energy Utilization
Lei Huang, Jingyi Ning, Yunyun Yang, Chong Tian, Jiahao Lv, Fanhao Zeng, Qiang Liu, Fuqi Zhao, Xufu Cai, Weibo Kong
Abstract
Phase change composites (PCCs) integrated with leakproof characteristics, high thermal conductivity, and excellent photoabsorption ability have been proven to be of great use in many fields. However, the real-life application of most of the reported PCCs remains challenging due to their strong fragility and inferior mechanical performance. Meanwhile, solid–solid phase change materials (SSPCMs) based on molecularly engineered structures exhibit intrinsic flexibility but lack thermal conductive and photoabsorption ability. So, it is significative and critical to combine the merits of SSPCMs and PCCs for the real-life application. Herein, we introduced PEG8K and graphene nanoplates (GNPs) into a dynamic cross-linked polymeric skeleton to yield dynamic SSPCM-based composites (DSSPCCs). The fabricated DSSPCCs underwent a leak-free phase change process with a high enthalpy value (93.74 J/g) and showed excellent stability and mechanical flexibility. Meanwhile, the DSSPCC with 3 wt % GNPs exhibited higher thermal conductivity (1.071 W·m–1 K–1) than other reported SSPCM-based composites and excellent photo-to-thermal conversion ability (temperature reached 120 °C within 65 s under near-infrared irradiation). Moreover, our DSSPCCs possessed outstanding recyclability and solid-state plasticity, originating from the dynamic feature of urethane bonds. The excellent comprehensive properties of the DSSPCCs guarantee they are suitable to be used as various thermal interface materials, thermal energy storage units, and energy saving building materials.