Polystyrene colloids (PS) were prepared by soap-less emulsion (diameter: 0.2 to 1 μm) or dispersion polymerization (diameter: > 1µm). We modified the surface to render their coating with a smooth silica shell possible. Thereafter, the core can easily be removed by calcinations or dissolved in THF.

Alternatively, the PS surface can be decorated with silica particles. Their average number and size can be tuned by composition. These hybrid particles can be coated by a smooth silica shell, providing good mechanical stability of the rough shell after removing the PS core. Furthermore, silica coating enables easy surface modification.

Both, the PS core or the silica shell can be fluorescent-labeled. Beside of these particles we synthesize monodisperse fluorescent-labeled PMMA particles as well as dumbbells.

• L. Zhang, M. D’Acunzi, M. Kappl, G. K. Auernhammer, D. Vollmer, C. M. van Kats, and A. van Blaaderen; Hollow Silica Spheres: Synthesis and Mechanical Properties. Langmuir, 25, (2009), 2711-2717.
• M. D'Acunzi, L. Mammen, M. Singh, X. Deng, M. Roth, G. K. Auernhammer, H.-J. Butt and D. Vollmer: Superhydrophobic surfaces by hybrid raspberry-like particles. Faraday Discussion 146, to be published