Synthesis of Daisy-Shaped and Multipod-like Silica/Polystyrene Nanocomposites

The synthesis of composite particles with original morphologies resulting from the combination of an inorganic silica seed and polymer nodules is reported. To promote association between both components, the silica seeds are previously functionalized with an appropriate coupling agent carrying polymerizable groups. Following classical recipes, emulsion polymerization of styrene is achieved in the presence of these surface-modified particles and polystyrene is formed exclusively at the surface of the inorganic precursors. The density of the coupling agent, however, as well as the silica seed diameter have a strong influence on the particle morphology. In the case when this density is equal to 0.1 molecule nm-2 (that is around 0.17 × 10-6 mol m-2) and the seed size is close to 170 nm, an interesting evolution of the morphology with the reaction time, from daisy-like toward multipod-like, is observed. Thus, the possibility to elaborate original building blocks with a defined shape and size is demonstrated.