Zinc antimonate nanoparticles consisting of antimony and zinc oxide were surface modified in a methanol solvent medium using triethoxysilane-based atom transfer radical polymerization (ATRP) initiating group (i.e.,) 6-(2-bromo-2-methyl) propionyloxy hexyl triethoxysilane. Successful grafting of ATRP initiator on the surface of nanoparticles was confirmed by thermogravimetric analysis that shows a significant weight loss at around 250-410 degrees C. Grafting of ATRP initiator onto the surface was further corroborated using Fourier transform Infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The surface-initiated ATRP of methyl methacrylate (MMA) mediated by a copper complex was carried out with the initiator-fixed zinc antimonate nanoparticles in the presence of a sacrificial (free) initiator. The polymerization was preceded in a living manner in all examined cases; producing nanoparticles coated with well defined poly(methyl methacrylate) (PMMA) brushes with molecular weight in the range of 35-48K. Furthermore, PMMA-grafted zinc antimonate nanoparticles were characterized using Thermogravimetric analysis (TGA) that exhibit significant weight loss in the temperature range of 300-410 degrees C confirming the formation of polymer brushes on the surface with the graft density as high as 0.26-0.27 chains/nm(2). The improvement in the dispersibility of PMMA-grafted zinc antimonate nanoparticles was verified using ultraviolet-visible spectroscopy and transmission electron microscopy. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 5092-5099, 2010