Wetting of doubly periodic rough surfaces in Wenzel’s regime

¹ Institute of Mechanics, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
² ETH Zurich, Computational Physics for Engineering Materials, CH-8093 Zurich, Switzerland

^* Corresponding author: stani@imbm.bas.bg

Abstract

In this work we present preliminary results from our numerical study of the shapes of a liquid meniscus in contact with doubly sinusoidal rough surfaces in Wenzel’s wetting regime. Using the full capillary model we obtain the advancing and the receding equilibrium meniscus shapes for a broad interval of surface roughness factors. The contact angle hysteresis is obtained when the three-phase contact line is located on one row (block case) or several rows (kink case) of physical defects. We find that depending on the mutual disposition of the contact line and the lattice of periodic defects, different stick-slip behaviors of the contact line depinning mechanism appear, leading to different values of the contact angle hysteresis.