Synthesis of Magnetic Polystyrene Nanoparticles Using\nAmphiphilic Ionic Liquid Stabilized RAFT Mediated Miniemulsion Polymerization

Abstract

Imidazole\nbased amphiphilic ionic liquids (ILs) were used as surfactants\nin miniemulsion polymerization (MEP) of styrene using a free radical\nprocess as well as reversible addition–fragmentation chain\ntransfer (RAFT). Monodisperse polystyrene (PS) nanoparticles were\nobtained, demonstrating the efficiency of the amphiphilic IL as surfactant\nin MEP. IL stabilized miniemulsion was furthermore used to prepare\npolystyrene based magnetic nanoparticles (MNP). A large increase of\nthe possible MNP content associated with very good colloidal stability\nwas achieved using IL stabilized RAFT mediated MEP where a carboxyl\nfunctionalized chain transfer agent (CTA) was applied, allowing interaction\nwith the MNP surface. The molecular weight and dispersity index of\npolystyrene, the content of MNP, and the morphologies of the hybrid\nnanoparticles were controlled by proper optimization of the concentration\nof initiator and CTA. The materials have been analyzed by NMR, GPC,\nDLS, SEM, TEM, and TGA. Finally, the magnetic properties of the materials\nwere determined by vibrating sample magnetometer (VSM) analysis.