Summary: Surface functionalization of Fe3O4 magnetic nanoparticles (MNP) via living radical graft polymerization with styrene and acrylic acid (AAc) in the reversible addition‐fragmentation chain transfer (RAFT)‐mediated process was reported. Peroxides and hydroperoxides generated on the surface of Fe3O4 nanoparticles via ozone pretreatment facilitated the thermally initiated graft polymerization in the RAFT‐mediated process. A comparison of the MNP before and after the RAFT‐mediated process was carried out using transmission electron microscopy (TEM) analysis, Fourier transform infrared (FTIR), and X‐ray photoelectron spectroscopy (XPS). Gel permeation chromatography (GPC) was used to determine the molecular weight of the free homopolymer in the reaction mixture. Well‐defined polymer chains were grown from the MNP surfaces to yield particles with a Fe3O4 core and a polymer outer layer. The resulting core–shell Fe3O4‐g‐polystyrene and Fe3O4‐g‐poly(acrylic acid) (PAAc) nanoparticles formed stable dispersions in the organic solvents for polystyrene (PS) and PAAc, respectively.
Schematic illustration of thermally induced graft polymerization of styrene and AAc with the ozone‐treated Fe3O4 MNP.
