Leak-free and shape-stabilized phase change composites with radial spherical SiO2 scaffolds for thermal management

Microencapsulated core–shell structures have proven to be an effective means for realizing high-enthalpy and shape-stabilized phase change materials (PCMs), but the low heat and shear resistance of the shell material seriously restrict their practical application in functional materials. Here, leak-free and shape-stabilized PCMs were fabricated by a strategy of confinement of phase change media via capillary adsorption on synthetic radial spherical silica (RSSiO2) scaffolds. The organic and inorganic components exchange the traditional core–shell positions, forming a new phase change composite with an inorganic material as the core layer. It not only endowed this composite with high-temperature regulation ability but also its enthalpy value was stabilized at 96.0 J g−1 after the heat treatment process. More importantly, its heat-resistant stability was significantly improved, reaching above 300–350 °C. This indicates that the core structure of inorganic RSSiO2 could not merely solve the inherent defects of conventional microcapsules but provides higher thermal stability as well, which is expected to be applied in high-temperature melt fiber spinning and electrical thermal management of devices.