Berlin 2015 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 54: Wetting, Micro and Nanofluidics (joint session CPP, DY)

CPP 54.6: Vortrag

Mittwoch, 18. März 2015, 16:15–16:30, C 243

Dynamic Contact Angle of a Soft Linear Viscoelastic Solid — •Stefan Karpitschka¹, Siddhartha Das², Mathijs van Gorcum¹, Hugo Perrin³, Bruno Andreotti³, and Jacco H. Snoeijer^1,4 — ¹Physics of Fluids Group, Faculty of Science and Technology, Mesa+ Institute, University of Twente, 7500 AE Enschede, The Netherlands — ²Department of Mechanical Engineering, University of Maryland, College Park, MD 20742, USA — ³Physique et Mécanique des Milieux Hétérogènes, UMR 7636 ESPCI -CNRS, Univ. Paris-Diderot, 10 rue Vauquelin, 75005, Paris, France — ⁴Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands

The wetting motion of a liquid over a rigid solid gives rise to a dynamic liquid contact angle. Here we show that on a soft, viscoelastic substrate, a moving contact line leads to a dynamic contact angle of the solid. The initially flat solid surface is deformed elastically into a sharp ridge. The ridge shape and the orientational angle of its tip depend on the contact line velocity. We present a theory based on linear response that reveals how the dynamics of the wetting ridge emerges from the substrate rheology. The theory is validated experimentally with measurements of the dynamic contact angle on a silicone gel.