Functionalization of iron oxide magnetic nanoparticles with poly(methyl methacrylate) brushes via grafting-from atom transfer radical polymerization

A key problem with nanomaterials is the difficulty of controlling the dispersion of nanoparticles inside an organic medium. To overcome this problem, functionalization of the nanoparticle surface is required. Poly(methyl methacrylate) (PMMA) brushes were grown on the surface of iron oxide magnetic nanoparticles with atom transfer radical polymerization and a grafting‐from approach. Modified magnetic nanoparticles with a graft density of 0.1 PMMA chains/nm2 were obtained. Cu(II), used as a deactivating complex, allowed good control of the polymerization along with a narrow polydispersity of the polymer chains. The functionalized magnetic nanoparticles were characterized with Fourier transform infrared spectroscopy, thermogravimetric analysis, gel permeation chromatography, and atomic force microscopy. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 925–932, 2007 Poly(methyl methacrylate) (0.1 chains/nm2) was grown on the surface of iron oxide magnetic nanoparticles by atom transfer radical polymerization and a grafting‐from approach. Copper bromide and 2,2′‐bipyridine were used as catalysts. Good control of the polymerization and a narrow polydispersity of the polymer brushes were obtained with Cu(II) as a deactivating complex.