| Autor: |
Thiele U, Snoeijer JH; Physics of Fluids Group and J. M. Burgers Centre for Fluid Dynamics , University of Twente , P.O. Box 217, 7500 AE Enschede , The Netherlands., Trinschek S; Université Grenoble-Alpes , CNRS, Laboratoire Interdisciplinaire de Physique , 38000 Grenoble , France., John K; Université Grenoble-Alpes , CNRS, Laboratoire Interdisciplinaire de Physique , 38000 Grenoble , France. |
| Jazyk: |
angličtina |
| Zdroj: |
Langmuir : the ACS journal of surfaces and colloids [Langmuir] 2018 Jun 19; Vol. 34 (24), pp. 7210-7221. Date of Electronic Publication: 2018 Jun 07. |
| DOI: |
10.1021/acs.langmuir.8b00513 |
| Abstrakt: |
The three-phase contact line of a droplet on a smooth surface can be characterized by the Young equation. It relates the interfacial energies to the macroscopic contact angle θ e . On the mesoscale, wettability is modeled by a film-height-dependent wetting energy f( h). Macro- and mesoscale descriptions are consistent if γ cos θ e = γ + f( h a ), where γ and h a are the liquid-gas interface energy and the thickness of the equilibrium liquid adsorption layer, respectively. Here, we derive a similar consistency condition for the case of a liquid covered by an insoluble surfactant. At equilibrium, the surfactant is spatially inhomogeneously distributed, implying a nontrivial dependence of θ e on surfactant concentration. We derive macroscopic and mesoscopic descriptions of a contact line at equilibrium and show that they are consistent only if a particular dependence of the wetting energy on the surfactant concentration is imposed. This is illustrated by a simple example of dilute surfactants, for which we show excellent agreement between theory and time-dependent numerical simulations. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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