Preparation and characteristic of palmitic acid/flower-shaped CuS composite phase change material for effective heat storage and photothermal conversion

Designing and synthesizing the excellent heat storage and photothermal integrated composite phase change materials (PCMs) is an effective strategy for solar energy utilization. This work focuses on two kinds of CuS (cuboidal and 3D flower-shaped) with different morphology were designed as substrates and photothermal materials, and PA/F–CuS and PA/C–CuS composite PCMs have been prepared by melt-blending and vacuum impregnation method. Through SEM and pore structure characterization as well as leakage testing, it is proved that 3D layered flower-shaped CuS not only exposes the large specific surface area and rich adsorption sites, but also 2D thin layers can perform multiple reflections to improve the utilization rate of solar energy. The flower-shaped CuS is more suitable for the supporting material. Noteworthy, the latent heat of PA/F–CuS can reach 226.3 J/g, and the thermal conductivity is 0.3447 W/(m·K). Furthermore, compared with pure PA, the photothermal property of PA/F–CuS increased by 49.22–84.59%, and the photothermal conversion efficiency can reach 70.3%. This work provides an innovative idea for the design and manufacture of composite PCMs related to medium and low temperature solar energy storage, and has broad application potential in the field of thermal energy storage such as solar energy utilization and building insulation materials.