Flexible HMF/HTC/PEG composite foam with photothermal conversion, energy storage, and shape memory for adaptive thermal management

Phase change materials (PCMs) face critical challenges in practical applications, including leakage, low thermal conductivity, rigidity, and limited responsiveness to external stimuli. To address these issues, this study developed a flexible phase-change composite foam (HMF/HTC/PEG) integrating photothermal conversion, leakage-proof, energy storage, and light-driven shape memory capabilities. Hydrothermal carbon (HTC) particles derived from glucose were synthesized to enhance photothermal conversion, while hybrid melamine foam (HMF) with a three-dimensional porous network served as a flexible matrix. By leveraging π-π interactions between carboxyl-rich HTC particles and HMF, a robust photothermal platform was constructed. Diphenylmethane diisocyanate (MDI) cross-linking further immobilized polyethylene glycol (PEG) within the HMF/HTC framework, forming an interpenetrating network to prevent leakage. The composite exhibited a high latent heat, rapid temperature rise under light irradiation, and high shape recovery efficiency. The material demonstrated dual functionality in thermal management: absorbing excess heat in high-temperature environments and converting solar energy into stored thermal energy for controlled release in cold conditions. Its lightweight, elastic, and shape-adaptive properties enable applications in flexible electronics and energy-efficient buildings. This work proposes an innovative multifunctional PCMs framework, bridging the gap between advanced energy storage and adaptive thermal management technologies.