Encapsulated and shape‐stabilized phase change composites with photothermal conversion and latent thermal storage properties: A review

Abstract Photothermal phase change composites (PTPCCs) utilize sunlight as an excitation source, combining photothermal materials with phase change materials (PCMs). In this process, photothermal materials capture sunlight and convert it into thermal energy; PCMs store thermal energy in the form of latent heat through their inherent physical state change. This provides a new route to expanding the application scope of PCMs and alleviating constraints with respect to energy supply. Notably, polymers play a critical role in optimizing the performance of PTPCCs. Polymers such as poly(methyl methacrylate), polyurethane, polyacrylamide and sodium alginate serve as supporting matrices to improve shape stability of PTPCCs and suppress leakage from PCMs. Polydopamine and polypyrrole act as effective photothermal components to improve photothermal conversion efficiency. In this paper, the photothermal conversion mechanism of photothermal materials is firstly elaborated. Subsequently, four preparation methods of PTPCCs are systematically introduced, involving melt blending, micro‐/nanocapsule encapsulation, electrospinning and porous adsorption. Meanwhile, the photothermal conversion and storage energy efficiencies are compared. Then, the applications of PTPCCs are discussed in the field of wearable fabrics, energy‐efficient buildings, desalination and photothermal therapy. Finally, the key issues and severe challenges existing in the research of PTPCCs are also pointed out, providing insights and directions for the further exploration of phase change composites with excellent comprehensive performance. © 2026 Society of Chemical Industry.