Berlin 2012 – scientific programme
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 21: Poster: Wetting, Micro and nanofluidics
CPP 21.8: Poster
Wednesday, March 28, 2012, 11:00–13:00, Poster A
Dynamics of liquid-liquid dewetting — •Stefan Bommer1, Sebastian Jachalski2, Dirk Peschka2, Barbara Wagner2, and Ralf Seemann1 — 1Saarland University,Saarbrücken — 2Weierstrass Institute, Berlin
We investigate the dewetting behavior of liquid polystyrene films (PS) from an underlying liquid poly(methyl)acrylate (PMMA) substrate. To understand the dynamics and the characteristics of liquid-liquid dewetting we explore the entire dewetting process from film rupture to the final droplet shape by in-situ scanning force microscopy (AFM). The nanometric polymer films are prepared in an non-equilibrium, glassy state and the dewetting process is started by heating the polymer films above their respective glass transition temperatures. The system is solidified by a fast reduction of temperature and the solidified liquid-liquid interface can be imaged by AFM after removing the upper PS structures using a selective solvent. Correlating both interfaces the 3d-shape of the dewetting structures can be determined. From the equilibrium droplet shapes and the resulting contact angles we can e.g. determine the ratio of the interfacial energies. The thus determined parameters are used as input parameter for numerically simulated dewetting processes which are compared to experimental results.