Synergistic enhancement of photothermal energy storage capacity of polyethylene glycol by polydopamine and nano-copper particles

Phase change materials (PCMs) are a crucial focus of research in the field of photothermal energy storage. However, due to their inherently low photothermal conversion efficiency, traditional PCMs absorb solar energy scarcely. The photothermal conversion ability of PCMs are usually enhanced by incorporating photothermal conversion nanoparticles. Polydopamine (PDA) is widely used in various fields due to its excellent photothermal conversion and adhesion performance. We dispersed PDA into PEG containing CuNPs to test the effect of PDA on thermal properties of cPCMs. Our team has conducted experiments to test the thermal characteristics and photothermal conversion ability of cPCMs. Results demonstrated that the addition of PDA mitigated the enthalpy loss caused by integrating CuNPs. The enthalpy of melting of cPCMs with addition of polydopamine is greater than that without polydopamine for the composites with different mass fractions. The addition of PDA in cPCMs enhanced their photothermal conversion capacity, resulting in higher temperatures being achieved within the same exposure time compared to samples without PDA. Therefore, the cPCMs with dispersed polydopamine can store higher energy. Meanwhile, PDA also improved the overall thermal conductivity of the material. Our work provided a new method to utilize the photothermal properties of polydopamine. Meanwhile, it can reduce the cost of photothermal energy storage PCMs and further improve the potential of PCM energy storage.