Epoxy‐silica nanocomposites: Preparation,experimental characterization,and modeling

Silica nanoparticles having different sizes were obtained by the sol‐gel process and characterized. The prepared nanoparticles were subsequently used as reinforcing fillers to prepare epoxy‐based composites with a silica content ranging from 1 to 5 wt %. SEM analysis and tensile tests carried out on the silica‐epoxy nanocomposites indicated the absence of particle aggregation and a reinforcing effect in terms of increased elastic modulus. Mechanical properties were also modeled by using a finite element code able to construct a numerical model from a microstructural image of the material. A more reliable model was prepared by considering the presence of an interphase layer surrounding the particles with intermediate elastic properties between the epoxy and the inclusions and a characteristic size proportional to the particle radius. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2382–2386, 2005