Regioselective Coating of Tetrapod-like Clusters with Silica
Résumé
We describe an easy procedure to regioselectively coat binary tetrapod-like silica/
polystyrene clusters with silica. First we show that the addition of tetraethoxysilane into a basic hydroalcoholic suspension of binary tetrapods induces the preferential growth of their silica core, which conforms to the shape of the polystyrene nodules while growing. On the contrary, we show that the formation of a continuous silica shell around the clusters is promoted if silanol groups have been incorporated at the surface of the polystyrene nodules before the addition of tetraethoxysilane. The thickness and the roughness of the silica coating can be tuned by varying several experimental
parameters.