Dresden 2017 – wissenschaftliches Programm
CPP 62.5: Vortrag
Donnerstag, 23. März 2017, 16:00–16:15, ZEU 255
Elasto-Capillary Interactions in the Absence of a Contact Line — Marco Rivetti1, Thomas Salez2, Maxence Arutkin2, Chung-Yuen Hui3, Elie Raphael2, and •Oliver Bäumchen1 — 1Max Planck Institute for Dynamics and Self-Organization (MPIDS), D-37077 Göttingen, Germany — 2UMR Gulliver, CNRS and ESPCI ParisTech, PSL University, Paris, France — 3Department of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, USA
A thin liquid film with non-zero curvature at its free surface spontaneously relaxes towards a flat configuration. This flow is driven by Laplace pressure gradients and resisted by the liquid's viscosity. In the last few years, we have studied the dynamics of this system experimentally, numerically and analytically (e.g. Rivetti et al., Soft Matter 11, 2015, McGraw et al., PRL 109, 2012). Inspired by recent progresses on the wetting behaviour and the dynamics of liquid droplets on soft substrates, we here consider the relaxation of a thin viscous film supported by an elastic foundation. We present experiments involving thin PS films on PDMS substrates, where the dynamics of the liquid-air interface is monitored by AFM. In this system, Laplace pressure gradients not only drive the flow, but they also induce elastic deformations on the substrate. These deformations affect the flow and the shape of the liquid-air interface itself, giving rise to an original example of an elasto-capillary interaction that is not mediated by the presence of a contact line. We also discuss a theoretical model and simulations that describe the coupled evolution of the substrate-liquid and the liquid-air interface.