Controllable synthesis of anisotropic silica/polymer composite particles via seeded dispersion polymerization

In this work, seeded dispersion polymerization was adopted to prepare anisotropic silica/polymer composite particles with controllable sizes and morphologies using the surface-modified silica particles as the seeds. Through this approach, submicron-sized silica/polymer particles with snowman-like, dumbbell-like, raspberry-like and core-shell structures could be easily fabricated in large scale. Many factors that might affect the morphologies of composite particles including the weight ratio of monomer/silica seeds, the polarity of reaction medium, reaction temperature, reaction time, the amount of crosslinking agent or the polarity of monomers were investigated. The results indicate that the interfacial tension between PS phases and SiO2 particles and the coalescence between growing polymer nodules over silica particles are responsible for the formation of different particle morphologies. It is interesting that snowman-like SiO2/PS particles could be afforded by two different processes: one was normally transformed from raspberry-like particles via the coalescence between growing polymer nodules; the other was formed directly at a high content of monomer. These different morphological particles may have important applications in biological/medical materials, optical materials, sensors, catalyst support, colloidal stabilizer, etc. (C) 2017 Elsevier B.V. All rights reserved.