Design of microencapsulated phase change material by one-step swelling polymerization in Pickering emulsion

Microencapsulated phase change materials (MePCMs) based on swelling polymerization in Pickering emulsion were demonstrated. Monodisperse poly(glycidyl methacrylate-co-2-hydroxyethyl methacrylate) P(GMA-co-HEMA) particles were prepared by dispersion polymerization. The introduction of hydrophilic monomer HEMA endowed the obtained particles with suitable surface hydrophilicity for stabilizing Pickering emulsion. MePCMs with PGMA–polystyrene interpenetrating composite shell were formed when non-crosslinked particles were employed as stabilizer, while MePCMs with particles-embedded shell were prepared with crosslinked particles as Pickering stabilizer. Phase change property, thermal stability and thermal reliability of two kinds of MePCMs were investigated by TGA, FT-IR, DSC and cycling test. The temperature of 10% weight loss of MePCMs with interpenetrating shell was 11 °C higher than that of MePCMs with particles-embedded shell. After cycling test, the percentage of leached core materials from MePCMs with interpenetrating shell was approximately one-third of that from MePCMs with particles-embedded shell. The results showed that MePCMs with an integral shell presented better thermal stability, tightness and thermal reliability than MePCMs with particles-embedded shell. The research developed a simple process for MePCMs with excellent performance.