title: Surface Fraction Dependence of Contact Angles Induced by Kinks in the Triple Line.
abstract: On periodic superhydrophobic surfaces the receding contact angle often scales with the surface fraction, as expected from a simple rule of mixture, the Cassie relation. However, it has been argued that energy averaging breaks down owing to line pinning, and that line fraction scaling should apply instead. From experiments and simulations we show that proper inclusion of triple line defects introduce surface fraction scaling in the line depinning threshold. In contrast to the Cassie relation and in agreement with the data, this dependence is strongly nonlinear due to triple line elasticity.
authors.affiliation: Surface du Verre et Interfaces, UMR 125 CNRS/Saint-Gobain, 39 Quai Lucien Lefranc, F-93303 Aubervilliers, Cedex, France.
authors.forename: M
authors.initials: M
authors.lastname: Rivetti
authors.affiliation: Surface du Verre et Interfaces, UMR 125 CNRS/Saint-Gobain, 39 Quai Lucien Lefranc, F-93303 Aubervilliers, Cedex, France.
authors.forename: J
authors.initials: J
authors.lastname: Teisseire
authors.affiliation: École Supérieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI) ParisTech, PSL Research University, Sciences et Ingénierie de la matière Molle, CNRS UMR 7615, 10, Rue Vauquelin, F-75231 Paris Cedex 05, France and Sorbonne-Universités, UPMC Université Paris 06, SIMM, 10, Rue Vauquelin, F-75231 Paris Cedex 05, France.
authors.forename: E
authors.initials: E
authors.lastname: Barthel