title: Slip-mediated dewetting of polymer microdroplets.
abstract: Classical hydrodynamic models predict that infinite work is required to move a three-phase contact line, defined here as the line where a liquid/vapor interface intersects a solid surface. Assuming a slip boundary condition, in which the liquid slides against the solid, such an unphysical prediction is avoided. In this article, we present the results of experiments in which a contact line moves and where slip is a dominating and controllable factor. Spherical cap-shaped polystyrene microdroplets, with nonequilibrium contact angle, are placed on solid self-assembled monolayer coatings from which they dewet. The relaxation is monitored using in situ atomic force microscopy. We find that slip has a strong influence on the droplet evolutions, both on the transient nonspherical shapes and contact line dynamics. The observations are in agreement with scaling analysis and boundary element numerical integration of the governing Stokes equations, including a Navier slip boundary condition.
authors.affiliation: Soft Matter Physics Group, Experimental Physics, Saarland University, 66041 Saarbrücken, Germany; Département de Physique, Ecole Normale Supérieure/Paris Sciences et Lettres (PSL) Research University, CNRS, 75005 Paris, France; joshua.mcgraw@phys.ens.fr.
authors.forename: Joshua D
authors.initials: JD
authors.lastname: McGraw
authors.affiliation: Fluid Interfaces Group, Experimental Physics, Saarland University, 66041 Saarbrücken, Germany; Department of Complex Fluids, Max Planck Institute for Dynamics and Self-Organization, 37077 Göttingen, Germany;
authors.forename: Tak Shing
authors.initials: TS
authors.lastname: Chan
authors.affiliation: Soft Matter Physics Group, Experimental Physics, Saarland University, 66041 Saarbrücken, Germany;
authors.forename: Simon
authors.initials: S
authors.lastname: Maurer
authors.affiliation: Laboratoire de Physico-Chimie Théorique, UMR Gulliver 7083, Ecole Supérieure de Physique et de Chimie Industrielles ParisTech/PSL Research University, 75005 Paris, France;
authors.forename: Thomas
authors.initials: T
authors.lastname: Salez
authors.affiliation: Laboratoire de Physico-Chimie Théorique, UMR Gulliver 7083, Ecole Supérieure de Physique et de Chimie Industrielles ParisTech/PSL Research University, 75005 Paris, France;
authors.forename: Michael
authors.initials: M
authors.lastname: Benzaquen
authors.affiliation: Laboratoire de Physico-Chimie Théorique, UMR Gulliver 7083, Ecole Supérieure de Physique et de Chimie Industrielles ParisTech/PSL Research University, 75005 Paris, France;
authors.forename: Elie
authors.initials: E
authors.lastname: Raphaël
authors.affiliation: Fluid Interfaces Group, Experimental Physics, Saarland University, 66041 Saarbrücken, Germany; Department of Complex Fluids, Max Planck Institute for Dynamics and Self-Organization, 37077 Göttingen, Germany;
authors.forename: Martin
authors.initials: M
authors.lastname: Brinkmann
authors.affiliation: Soft Matter Physics Group, Experimental Physics, Saarland University, 66041 Saarbrücken, Germany; Leibniz-Institute for New Materials, 66123 Saarbrücken, Germany.
authors.forename: Karin
authors.initials: K
authors.lastname: Jacobs
keywords: contact line motion; free-surface flows; microflows; nanoflows; slip