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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 30.2: Poster
Mittwoch, 13. März 2013, 16:30–18:30, Poster C
Droplet morphologies upon growing and shrinking on triangular grooved substrates — •Carsten Herrmann1, Ciro Semprebon2, Martin Brinkmann1,2, and Ralf Seemann1 — 1Saarland University, 66041 Saarbrücken — 2Max Planck Institute for Dynamics and Self-Organization, 37018 Göttingen
We experimentally investigate the morphologies of droplets sitting on triangular grooved micro-structures upon volume change. The droplet morphologies are characterized by their eccentricity, i.e. the ratio of width to length, as function of the number of wetted grooves. The eccentricity of small droplets wetting just a few grooves characteristically varies upon an increase in drop volume and arrives at a constant value for sufficiently large droplets. In contrast droplets are almost perfectly round upon volume reduction for sufficiently small droplet volumes. In both cases the morphological changes depend sensitively on the wettability and the wedge angle of the triangular grooved substrate. The experimental results are compared quantitatively with numerical results computed by minimizing surface energies.