Microencapsulation of hexadecane by surface-initiated atom transfer radical polymerization on a Pickering stabilizer

Abstract

Hexadecane-loaded microcapsules with SiO₂–poly(methyl methacrylate) (PMMA) hybrids as shells were prepared by surface-initiated atom transfer radical polymerization (SI-ATRP) in an oil-in-water Pickering emulsion. ATRP-initiators were introduced onto SiO₂ particles by a homemade silane coupling reagent containing a 2-bromoisobutyrate group. SI-ATRP polymerization was conducted on Pickering stabilizers based on activators regenerated by electron transfer (ARGET). TGA results indicated that 80.3% of PMMA chains in the shell were covalently-bonded to SiO₂, which was formed by SI-ATRP polymerization. The microcapsules show excellent potential for thermal energy storage, as evidenced by a high melting enthalpy of 161.7 J g⁻¹.