Regensburg 2022 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 17: Poster 2
CPP 17.14: Poster
Dienstag, 6. September 2022, 11:00–13:00, P2
Dewetting dynamics and equilibrium droplet shapes for of visco-elastic substrates — •Khalil Remini1, Leonie Schmeller2, Dirk Peschka2, Barbara Wagner2, and Ralf Seemann1 — 1Experimental Physics, Saarland University, Saarbrücken, Germany — 2Weierstrass-Institute, Berlin University, Berlin, Germany
In our study we are interested in the dewetting of liquid polymer layers (Polystyrene 18 kg/mol) with about 100 nm thickness from visco-elastic polydimethylsiloxane surfaces with elasticity ranging E = 1.2 MPa for Sylgard 184 to E = 3 kPa for Cy52-276. When heating the samples to temperatures where PS is liquid, holes nucleate in the initially uniform PS film. These holes grow during dewetting, coalesce and eventually form sessile droplets of a few micrometers in diameter sitting on the PDMS surface. Due to the particular situation of the adaptive PDMS substrate, we observe characteristic qualitative and quantitative differences in rim shapes, (dynamic) contact angles and dewetting velocities which are indicating differences in the underlying energy dissipation but might result also from potential phase separation of liquid and cross linked PDMS close to the three-phase contact line. To shed light on the impact of viscous and elastic properties and potential phase separation at the three phase contact line, we aim at a quantitative comparison of sessile (equilibrium) droplets on substrates having different elasticities and thus elastocapillary lengths.