title: High-frequency acoustic for nanostructure wetting characterization.
abstract: Nanostructure wetting is a key problem when developing superhydrophobic surfaces. Conventional methods do not allow us to draw conclusions about the partial or complete wetting of structures on the nanoscale. Moreover, advanced techniques are not always compatible with an in situ, real time, multiscale (from macro to nanoscale) characterization. A high-frequency (1 GHz) acoustic method is used for the first time to characterize locally partial wetting and the wetting transition between nanostructures according to the surface tension of liquids (the variation is obtained by ethanol concentration modification). We can see that this method is extremely sensitive both to the level of liquid imbibition and to the impalement dynamic. We thus demonstrate the possibility to evaluate the critical surface tension of a liquid for which total wetting occurs according to the aspect ratio of the nanostructures. We also manage to identify intermediate states according to the height of the nanotexturation. Finally, our measurements revealed that the drop impalement depending on the surface tension of the liquid also depends on the aspect ratio of the nanostructures. We do believe that our method may lead to new insights into nanoscale wetting characterization by accessing the dynamic mapping of the liquid imbibition under the droplet.
authors.affiliation: Université de Valenciennes et du Hainaut-Cambrésis , Institute of Electronics, Microelectronics and Nanotechnology, IEMN, UMR 8520, Le Mont Houy 59313, France.
authors.forename: Sizhe
authors.initials: S
authors.lastname: Li
authors.forename: Sebastien
authors.initials: S
authors.lastname: Lamant
authors.forename: Julien
authors.initials: J
authors.lastname: Carlier
authors.forename: Malika
authors.initials: M
authors.lastname: Toubal
authors.forename: Pierre
authors.initials: P
authors.lastname: Campistron
authors.forename: Xiumei
authors.initials: X
authors.lastname: Xu
authors.forename: Guy
authors.initials: G
authors.lastname: Vereecke
authors.forename: Vincent
authors.initials: V
authors.lastname: Senez
authors.forename: Vincent
authors.initials: V
authors.lastname: Thomy
authors.forename: Bertrand
authors.initials: B
authors.lastname: Nongaillard
mesh_terms: D000162:Acoustics; D049329:Nanostructures / Q000737:chemistry*; D017155:Wettability