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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 30: Poster: Focus: Wetting on smooth and rough surfaces: From spreading to superhydrophobicity

CPP 30.14: Poster

Mittwoch, 13. März 2013, 16:30–18:30, Poster C

Wetting of silica spheres on the micro-scale — •Jennifer Wenzl, René Stangenberg, and Günter K. Auernhammer — Max Planck Institute for Polymer Research, Mainz, Germany

We present here a model system for wet granular matter on the micrometer scale, which we are able to observe in 3D with confocal microscopy. We use a 3-phase-system consisting of polydisperse silica particles, dispersed in a mixture of an aqueous salt solution (sodium thiocyanate) and an organic solvent (cis-decaline). By mere shaking of the sample mixture, we generate capillary bridges and pickering emulsion droplets with cis-decaline as the binder liquid. Surface modification with methyl silyl groups allows us to adjust a finite contact angle of the interface between the binder liquid and the aqueous salt solution. With the combination of the confocal microscopy and a home-build nano-manipulation, we are able to apply a compression or shear load and observe simultaneously the sample structure in 3D.

We investigated the particle-droplet structure in 3D under compression and shear. In this presentation we show the wetting behavior of this interface and discuss the change of the emulsion droplet number and the corresponding volumes with time. We present also the structural changes of the particles depending on the applied load.