Dresden 2009 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 28: POSTERS Interfaces and Thin Films
CPP 28.14: Poster
Mittwoch, 25. März 2009, 17:00–19:00, P3
Collective behavior during dewetting — •Cristina-Maria Pop1, Ana Maria Florescu2, Yves Bréchet3, and Zoltán Néda4 — 1Arnold Sommerfeld Center and CeNS, Ludwig-Maximilians-Universität München, Germany — 2LSP, Université Joseph Fourier, St Martin d'Hères Cedex, France — 3SiMAP-ENSEEG, Institut National Polytechnique de Grenoble, St Martin d'Hères Cedex, France — 4Babeş-Bolyai University, Cluj-Napoca, Romania
When a liquid film on a substrate is unstable, dry spots appear and the liquid breaks into droplets: this phenomenon is called dewetting. It can be observed every day on a windshield or in a cooking pan, and the stability of liquid films on solid substrates is crucial for numerous technological applications. In biology, dewetting governs the dynamics of adhesion on wet substrates in the case of mushroom spores or living cells. Dewetting can take place through amplification of capillary waves in thin films, or by spontaneous nucleation and growth in thicker films.
We studied the mechanism of dewetting by introducing a two-dimensional model in which the dynamics of the dewetting hole is given by capillarity (the line tension which tends to shrink the hole, and the difference between the surface energy of the substrate when dry and wet). Dissipation makes the motion overdamped. With the aid of this model we performed numerical simulations which enabled us to find the critical parameters for the growth of a dewetting hole, and to study the collective dynamics of many holes in a dewetting process with spontaneous nucleation. Thus we obtained a size distribution of the liquid droplets on the substrate after dewetting has taken place.