High capacity and thermal stable phase-change microencapsulates via surfactant-free pickering emulsion polymerization

A novel hybrid-shell phase change materials (PCMs) was prepared via Pickering emulsion polymerization, exhibiting high thermal stability while maintaining a high latent heat. Using n-octadecane as the core, microencapsulated phase change materials (MicroPCMs) with PMMA@PS@SiO 2 hybrid shells were designed. The MicroPCMs achieved an enthalpy of 119.2 J/g, reaching 99.3% of the theoretical value, with an energy storage efficiency of 66.1% and a heat storage capacity of 99.8%. The temperature corresponding to 5% weight loss ( T 5% ) increased by 83 ℃, and the leakage rate remained as low as 5.6% after 200 cycles. The formation of the hybrid shell significantly enhanced the thermal stability and cycling durability of the MicroPCMs, while maintaining a high heat storage capacity and effectively addressing the leakage and cycling instability commonly existing in PCMs. Moreover, the surface-modified SiO 2 acted as a stabilizer to construct the Pickering emulsion template, enabling a green fabrication process. Finally, flexible PCM films were fabricated by melt blending and extrusion of MicroPCMs and poly(vinyl alcohol) (PVA), exhibiting excellent thermal management performance. Overall, the MicroPCMs demonstrate significant potential, with particular relevance and advantages in high-temperature processing areas.