Biphasic organohydrogels based on phase change materials with excellent thermostability for thermal management applications

Innovative thermal management materials are in high demand for construction of energy-efficient systems. Evaporative cooling hydrogel has been extensively investigated in passive building cooling owing to its cost-effective and environmental-friendly characteristics. However, poor mechanical properties and shape instability severely restrict its scope and lifespan. In this study, we report an ingenious and effective thermal management material, the PCMs organohydrogel, with advanced thermal performance and outstanding shape and thermal stability, which integrates the advantages of evaporative cooling performance of water and latent heat storage capability of eicosane. The biphasic PCMs organohydrogel was synthesized by the CAA-HRP-H2O2 ternary enzyme-mediated polymerization of the eicosane-in-water emulsion stabilized by the cellulose acetoacetate (CAA). CAA played important roles in the system not only as the emulsifier but also as the polymerization mediator. The encapsulation of PCMs by the organohydrogel provides the composites outstanding thermal stability as the decomposition temperature of the eicosane was elevated by 101 °C. Furthermore, the PCMs organohydrogel exhibits excellent thermomechanical performance and shape memory effect because of the wrapped phase-transition micro-inclusions and the interfacial tension of heterophases. The application of the PCMs organohydrogel as passive cooling material on the model house roof was demonstrated. The cooling effectiveness of the PCMs organohydrogel was investigated, indicating that the biphasic PCMs organohydrogel is expected to be an efficient and reliable passive thermal management material in building thermoregulations.