title: Effect of three-phase contact line topology on dynamic contact angles on heterogeneous surfaces.
abstract: Cassie-Baxter theory has traditionally been used to study liquid drops in contact with microstructured surfaces. The Cassie-Baxter theory arises from a minimization of the global Gibbs free energy of the system but does not account for the topology of the three-phase contact line. We experimentally compare two situations differing only in the microstructure of the roughness, which causes differences in contact line topology. We report that the contact angle is independent of area void fraction for surfaces with microcavities, which correspond to situations when the advancing contact line is continuous. This result is in contrast with Cassie-Baxter theory, which uses area void fraction as the determining parameter, regardless of the type of roughness.
authors.affiliation: Department of Mechanical Engineering, Tennessee Technological University, Cookeville, Tennessee 38501, USA.
authors.forename: Neeharika
authors.initials: N
authors.lastname: Anantharaju
authors.forename: Mahesh V
authors.initials: MV
authors.lastname: Panchagnula
authors.forename: Srikanth
authors.initials: S
authors.lastname: Vedantam
authors.forename: Sudhakar
authors.initials: S
authors.lastname: Neti
authors.forename: Svetlana
authors.initials: S
authors.lastname: Tatic-Lucic