Achieving heat storage coatings from ethylene vinyl acetate copolymers and phase change nano-capsules with excellent flame-retardant and thermal comfort performances

The heat-storage coatings from ethylene vinyl acetate (EVA) copolymers were developed by incorporating in-situ synthesized phase change nano-capsules (NEPCMs). The coatings were applied to the interior walls of the building, aimed at enhancing thermal storage and flame-retardant performances. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) are utilized to evaluate the chemical composition of the NEPCMs. At the same time, the thermal properties and microstructure of NEPCMs and the coatings are analyzed using differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The enthalpy of NEPCMs is 158.14 J/g, while that of heat-storage coatings is 56.45 J/g. NEPCMs and heat-storage coatings exhibit excellent thermal storage performance even after 200 heating-cooling cycles, demonstrating the excellent thermal stability of NEPCMs and heat-storage coatings. Furthermore, excellent flame-retardant properties are also provided by the heat-storage coating. In dynamic heat transfer experiments, under the same conditions, the heat-storage coatings were capable of maintaining the chamber in the thermal comfort zone (24-28 degrees C) for 141 min, while the conventional coatings lasted only 34 min. The results show that incorporating heat-storage coatings can effectively enhance the thermal regulation performance of interior walls and improve the thermal comfort of indoor environments. Therefore, heat-storage coatings hold a high potential for application in energy-saving buildings.