Styrene/Maleic Anhydride Macro‐RAFT‐Mediated Encapsulation

Summary: Luo et al. have published a method for the encapsulation of oil droplets by a polymer shell to form nanosized liquid‐filled particles. They use a water‐soluble styrene–maleic anhydride copolymer that carries a thiocarbonyl thio end‐group. This end‐group is able to induce reversible addition‐fragmentation chain transfer (RAFT)‐mediated polymerization, which leads to a miniemulsion polymerization‐like system. Here the polymerization is confined to the outer shell of a droplet/particle. Consequently, monomer is depleted from the centre of the particle, which leaves a liquid core surrounded by a polymer shell. The technique seems robust and opens up new pathways to nanostructured materials.Morphology development in the miniemulsion polymerization of styrene mediated by an aminolyzed STY/MAnh macro‐RAFT agent (black chains: the aminolyzed STY/MAnh copolymer, black dots: thiocarbonyl thio moieties that mediate the polymerization, red chains: styrene homopolymer).