Grafting of poly(2-hydroxyethyl methacrylate) on silica nanoparticles was accomplished via the sequential UV-induced graft polymerization. Under UV-irradiation, the silica was functionalized with the surface initiator, benzophenone (BP) and subsequently graft-polymerized with 2-hydroxyethyl methacrylate (HEMA). The grafting on the silica particles was confirmed by DSC analysis which revealed a shift of the glass transition temperature (T-g) of grafted PHEMA to higher temperature than T-g of ungrafted PHEMA. A significant improvement in the grafting efficiency and the grafting percentage was achieved when a sequential grafting approach was taken, employing multiple UV exposures. Using this approach, the efficient chain extension from the grafted-PHEMA was possible without producing significant amounts of ungrafted PHEMA when low HEMA concentrations were used during each UV-exposure. (c) 2014 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.