Preparation and Characterization of Novel EDTA-Functionalized Nanosilica

Surface modification is usually used to obtain reactive groups on silica nanoparticles. Most of the recent literatures concerning surface modification are based on surface grafting organosilanes onto silica [1,2]. However a very limited member of articles describes the modification of carboxyl group to silica nanoparticle surface [3].Stöber et al published a synthetic process for the fabrication of monodisperse silica particles via hydrolysis of tetraethylorthosilicate (TEOS) in an ethanol solution by stirring. This reaction is catalyzed by ammonia. Hydrolysis and condensation of alkoxide silicon led to monodisperse spheres of silica (nanosilica, NS). The particle diameters depend on TEOS, water, NH3 concentrations and temperature [4].In this work, surface of silica nanoparticles are modified with the grafting of 3-aminopropyl triethoxysilane (APTES) under sonication by one pot method to fabricate amine-functionalized silica nanoparticles (aminated nanosilica, ANS). Then, EDTA-functionalized nanosilica (EDTA-NS) was prepared as novel surface modified nanosilica. For this aim ANS react with ethylenediaminetetraacetic acid dianhydride (A-EDTA) at the mild conditions.The products were analysed and characterized by various methods such as FTIR spectroscopy and elemental analysis. Also, the morphology of all products was determined by a scanning electron microscope (SEM