Sodium acetate trihydrate/melamine foam composite PCM encapsulated by CuS/rGO modified epoxy resin and endowed with light-to-heat conversion properties

In this work, we proposed a novel strategy for the conversion and storage of photothermal energy. This strategy combined hydrothermally prepared CuS/rGO with commercial epoxy resin adhesives. The light-capturing capability of CuS and fast electron transfer rate of rGO was harnessed to endow the modified resin with photothermal conversion capability. Using an inorganic PCM as the energy-storage medium and melamine foam as its support carrier, a form-stabilized composite phase-change material with a latent heat of phase change of 233.7 J/g and a phase-change temperature of 48.7 °C was obtained. In addition, the pre-prepared MER was coated onto the surface of the CPCM. Its purpose was to utilize the photothermal conversion and waterproof properties of modified resins to store solar energy in the internal phase-change materials, while alleviating the leakage problem during the phase-change process of inorganic salt hydrate phase-change materials in the past. The leakage tests showed that the 1.0 mm thick MER provided excellent protection against leakage, significantly reducing leakage of the liquid phase and moisture escape. The composite phase-change material CPCM/MER demonstrated satisfactory results in photothermal conversion experiments. 2% CuS/rGO addition to CPCM/MER can complete the phase change. The samples also showed good stability in the cycling tests. After 100 cycles of testing, the latent heat of the CPCM only decreased by 5.13%. According to the FT-IR results, the CPCM also possessed chemical stability. In this study, a CPCM/MER was successfully prepared, extending the practical application of traditional inorganic phase-change materials in the field of solar energy storage.