Thermosensitive poly(ethylene glycol) methyl ether methacrylate (POEGMA) was grafted on SiO2 nanoparticles using activators generated by electron transfer atom transfer radical polymerization (AGET-ATRP) technique. The effects of the amount of ligand, catalyst, ascorbic acid and monomer, as well as the reaction temperature and time were systematically investigated and optimized to get a high grafting density. The structure of the hybrid materials was characterized by Fourier transform infrared (FTIR) spectroscopy, and the morphology was characterized by transmission electron microscopy (TEM) observations. Thermosensitive properties of SiO2-POEGMA particles were investigated at different grafting densities by turbidity measurements. (C) 2015 Elsevier B.V. All rights reserved.