Regensburg 2010 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 41: Nanoparticles and Composite Materials II

CPP 41.8: Talk

Thursday, March 25, 2010, 16:00–16:15, H48

Hybrid raspberry particles for superhydrophobic surfaces — •Doris Vollmer, Maria d'Acunzi, Lena Mammen, and Hans-Jürgen Butt — Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128, Mainz (Germany)

On superhydrophobic surfaces, water droplets roll off even at inclinations of just a few degrees, taking up any contaminants encountered on their way. In nature, the lotus leaf is one of the most efficient examples of a superhydrophobic surface. Its superhydrophobicity is conferred by surface roughness on the nano- and micrometer scale.

Here we report a novel method to prepare superhydrophobic films from raspberry particles. The term *raspberry particle* refers to the topography of their surfaces with nano-sized secondary spheres attached to a considerably larger primary particle. Our particles consist of a polystyrene core and a rough silica shell. The hybrid nature of our particles offers the possibility to design a completely new approach to prepare superhydrophobic surfaces.

Multilayers of particles are formed by evaporation of the aqueous dispersant. By exposure of the hybrid particles to tetrahydrofuran vapour, polystyrene leaks out of the core and forms bridges between the particles, thereby providing mechanical stability. The films are hydrophobized by silanization with a semifluorinate silane. Films show static contact angle for water of about 160° and roll-off angle of 1°.