Berlin 2012 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 17: Poster: Crystallisation, Nucleation and Self assembly

CPP 17.17: Poster

Tuesday, March 27, 2012, 18:15–20:15, Poster A

Monodisperse polystyrene@vinyl-SiO2 core-shell particles and hollow SiO2 spheres for photonic crystals fabrication — •Tian-Song Deng and Frank Marlow — Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany

SiO2-coated particles have been attracted much attention in recent years, since these core-shell particles have potential applications as chemical micro containers and colloidal crystals, and especially photonic crystals. In this paper a method of preparing highly monodisperse core-shell particles and hollow spheres is described. Both kinds of particles are very useful building-blocks for colloidal crystals. The key of the method is the use of vinyltrimethoxysilane as a precursor for the shells which are obtained by direct growth of vinyl-SiO2 on negatively charged PS template particles. This method delivers a tunable shell thickness (between 10 nm and 170 nm) combined with a very low polydispersity (smaller than 3%) and no aggregation of the obtained particles. Furthermore, the core-shell particles could be converted into hollow SiO2 spheres by removing the PS cores in a calcination process. Both, the PS@vinyl-SiO2 particles and the hollow SiO2 spheres can be self-assembled into colloidal crystals using their suspensions which are highly monodisperse and aggregation-free. The synthesis method might be extended for coating uniform organo-SiO2 shells on different kinds of core materials. In addition, the use of other organo-oxide precursors could lead to new hollow oxide particles useful for colloidal crystal formation.