BPCPPDYSOE21 – wissenschaftliches Programm
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DY: Fachverband Dynamik und Statistische Physik
DY 1: Wetting - organized by Stefan Karpitschka (Max Planck Institute for Dynamics and Self-Organization, Göttingen) (joint session CPP/DY)
DY 1.5: Hauptvortrag
Montag, 22. März 2021, 11:00–11:40, CPPb
Liquid-liquid Dewetting: From Spinodal Breakup to Dewetting Morphologies and Rates — •Ralf Seemann1, Roghayeh Shiri1, Stefan Bommer1, Dirk Peschka2, Sebastian Jachalski2, Lenoie Schmeller2, and Barbara Wagner2 — 1Saarland University, Experimental Physics, D-66123 Saarbücken — 2Weierstrass Institute, Mohrenstr. 39, D-10117 Berlin
The dewetting of liquid polystyrene (PS) from liquid polymethyl-methacrylate (PMMA) is studied. At dewetting temperatures, both polymers can be considered as Newtonian fluids with the same viscosity. Provided that the liquid PS layer is below 10 nm, breakup occurs by spinodal dewetting. Due to the low interfacial tension of the buried interface compared to the PS-air interface and the large mobility, a very short spinodal wavelength develops with a larger amplitude of the buried interface than that of the free PS-air interface. The spinodal patterns of PMMA-PS and PS-air interface are anti-correlated and the observed wavelength is within the range predicted from thin film models. For a later dewetting stage, when dewetting rims in the range of the PMMA film thickness have formed, characteristic profiles of both PMMA-PS and PS-air interface develop, which depend on the PMMA/PS thickness ratio. The dewetting rates are approximately linear but do not obey any well-defined scaling behavior. Based on the agreement of experimental results with theoretical predictions, we use the numerical simulations to predict local flow fields and energy dissipation that would otherwise be inaccessible to experiments.