Polyethylene glycol-based phase change materials with high photothermal conversion efficiency and shape stability in an aqueous environment for solar water heater

The development of composite phase change materials (PCM) with high photothermal conversion capability can effectively improve solar energy utilization. However, composite PCM loses the ability to encapsulate PCM in an aqueous/oil phase environment, limiting the practical scope of PCM applications. In our work, the composites stabilized in the aqueous phase were prepared using a free radical polymerization process. Composites have a high loading rate (85.1-89.0 wt%), high thermal conductivity (204% higher than PEG), high energy storage density (138.6 J/g), and high photothermal conversion efficiency (93.3%). Since PEG is encapsulated inside the structure during the polymerization of PAAAM, it can still encapsulate PEG even in the aqueous phase. Utilizing the heat storage characteristics of PEG and the high photothermal conversion characteristics of RHTC, composites can be used in solar water heater systems, reducing the operating costs and showing great application potential in aqueous phase environment.

Automated summary

Stabilized composite phase change materials prepared through free radical polymerization process in the aqueous phase exhibit high loading rate, thermal conductivity, energy storage density, and photothermal conversion efficiency, showing great application potential in solar water heater systems.