Applied Surface Science 257 (2011) 8581–8586 Contents lists available at ScienceDirect Applied Surface Science j our nal ho me p age: www.elsevier.com/loc ate/apsusc A novel method for the synthesis of polystyrene-graft-silica particles using random copolymers based on styrene and triethoxyvinylsilane Natalia A. Agudelo a , Leon D. Perez a,b,∗ , Betty L. Lopez a a Grupo Ciencia de los Materiales, Institute of Chemistry, University of Antioquia, Medellín, Colombia b Department of Materials Engineering, University of Antioquia, Calle 62 No. 52-59 SIU Lab 310, Medellin, Colombia a r t i c l e i n f o Article history: Received 8 February 2011 Received in revised form 4 May 2011 Accepted 4 May 2011 Available online 11 May 2011 Keywords: Silica Random copolymers Hybrid materials Polystyrene-grafted silica particles a b s t r a c t In the present research, random copolymers based on triethoxyvinylsilane (TEVS) and styrene (St) are synthesized and structurally characterized. According to the reactivity ratios of the monomers deter- mined by infrared analysis; St tends to form blocks whilst TEVS is expected to be incorporated as isolated units. A sample of poly(styrene-co-triethoxyvinylsilane) synthesized at low conversion using a monomer feeding ratio St:TEVS of 2:3 was used as macrosilane in the synthesis of polystyrene-g-silica particles. The grafting reaction was confirmed by infrared spectroscopy, thermogravimetric analysis and by the evaluation of the morphological characteristics of the hybrid particles. © 2011 Elsevier B.V. All rights reserved. 1. Introduction Inorganic nanoparticles have found numerous applications in fields such as medicine, design of electronic devices, catalysis and polymers reinforcement. Grafting polymer chains endows them unique functional properties and allows tailoring their sur- face characteristics to obtain materials with novel properties and applications. The dispersion of silica particles in aqueous media is enhanced by grafting the nanoparticles with water sol- uble polymers such as poly(oxyethylene methacrylate) and ionic poly(styrene sulfonic acid) [1]. In contrast, when silica particles are grafted with polystyrene (PS) a hydrophobic behavior is found [2,3]. Surface modified silica particles have potential application in dif- ferent technological fields, some of them are the reinforcement of polymers [4] and in the design of heterogeneous catalysts [5]. Dey et al. also report the synthesis of responsive hybrid nanoparticles by the reaction of an epoxy modified silica with a stimuli responsive poly (acrylic acid-N-isopropylacrylamide) [6]. The modification of inorganic materials, such as silica, requires the presence of functional groups on the surface of the parti- cles capable of either being involved in polymerization reaction or reacting with terminal groups of preformed polymers. Several strategies have been reported for grafting polymer chains to sil- ica particles. Linking covalently vinyl moieties to the surface of ∗ Corresponding author at: Department of Materials Engineering, University of Antioquia, Calle 62 No. 52-59 SIU Lab 310, Medellin, Colombia. Tel.: +57 4 2196547. E-mail address: ldperez@udea.edu.co (L.D. Perez). the particles followed by free radical polymerization of the corre- sponding monomer has been widely reported [2,7–9]. Comparable results are obtained when the silica surface is modified with a chain transference group [10]. Living polymerizations have been reported to be used for obtaining well defined silica nanoparticles grafted with poly- mers. Nitroxide-mediated polymerization is reported by Chevigny et al. for grafting silica particles with polystyrene [11]. Laru- elle et al. grafted silica nanoparticles with polystyrene-block- polybutylacrylate using stable free radical polymerization [12]. The use of reversible addition–fragmentation chain transference [13], atom transference radical polymerization [14] and anionic poly- merization [15] have also been reported. In the present research, we report the synthesis of random copolymers based on poly(styrene-co-triethoxyvinylsilane) and their application as macrosilanes for grafting silica particles with PS chains in a single step reaction. 2. Experimental 2.1. Materials Triethoxyvinylsilane (TEVS, 97% purity) and analysis grade styrene were purchased from Sigma–Aldrich (St. Louis, MO). Free radical initiator, i.e., 2,2-azobis-isobutyronitrile (AIBN), was supplied by Akzo Novel (Chicago, IL). Analytical grade toluene, methanol, butanol and tetrahydrofuran (THF) were purchased from Merck (Bogota, Colombia). The styrene monomer was distilled under reduced pressure at 135 ◦ C and the AIBN was recrystallized 0169-4332/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.apsusc.2011.05.021