Double-networked polypropylene-based leakage-proof phase change/radiative cooling films with high emissivity for remarkable cooling performance

Heat waves, increasingly frequent and intense, pose significant risks to social and economic activities. Thus personal thermal management based on typical petroleum-based fabrics such as polypropylene fabrics is gaining importance. To address these limitations of low latent heat, unsatisfied optical performance, and industrial production, a calcium alginate system was incorporated into a polypropylene matrix to form a secondary network that encapsulates phase change microcapsules (PCCs). This strategy effectively prevents PCCs from shedding while significantly enhancing the latent heat. Furthermore, the efficient incorporation of PCCs improved the optical properties of the obtained composites, with emissivity reaching 95.5 % and reflectivity increasing to 88.8 %. The enthalpy of the composite reached 132.2 J/g. Additionally, the composite demonstrated exceptional thermal performance, reducing temperatures by up to 11.2 °C (with an average reduction of 4.4 °C) during the day and 1.3 °C (average) at night. These results suggest that double-networked composite holds great potential for sustainable, energy-efficient thermal management and could pave the way for the development of innovative passive cooling materials and devices.