Passage of surfactant-laden and particle-laden drops through a contraction
| Autor: | Emilie Verneuil, Franz De Soete, Michael Levant, Laurence Talini, Nicolas Passade-Boupat, Léa Delance, François Lequeux |
|---|---|
| Přispěvatelé: | Sciences et Ingénierie de la Matière Molle (UMR 7615) (SIMM), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Physico-Chimie des Interfaces Complexes (PIC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Pôle d'Etude et de Recherche de Lacq [Total] (PERL) |
| Rok vydání: | 2021 |
| Předmět: |
Fluid Flow and Transfer Processes
Materials science Drop (liquid) Flow (psychology) Microfluidics Computational Mechanics 02 engineering and technology Mechanics Deformation (meteorology) 021001 nanoscience & nanotechnology 01 natural sciences 010305 fluids & plasmas Surface tension Coupling (electronics) Pulmonary surfactant Modeling and Simulation 0103 physical sciences [CHIM]Chemical Sciences Particle 0210 nano-technology |
| Zdroj: | Physical Review Fluids Physical Review Fluids, American Physical Society, 2021, 6 (9), ⟨10.1103/PhysRevFluids.6.093601⟩ |
| ISSN: | 2469-990X |
| DOI: | 10.1103/physrevfluids.6.093601 |
| Popis: | International audience; We report on the experimental behavior of oil drops suspended in water and passing in a constricted capillary tube under an imposed pressure gradient. The surfaces of droplets are covered either by colloidal solid particles or soluble surfactants. We investigate the coupling between the flow behavior and the concentration gradient in adsorbed species that are induced by surface expansion, when a water lubrication film persists between the drop and the capillary walls. For both particle-laden and surfactantladen drops, we evidence the formation of strong concentrations gradients resulting in surface tension gradients. We show how local values of surface tension can be monitored using flowrate measurements. In the case of particle-laden drops, we demonstrate the surface tension gradient is balanced by viscous friction in the lubrication film. In the case of surfactant-laden drops, we suggest a Marangoni flow opposes the decrease of surfactant concentration at the front of the drop, up to a threshold value of the surface expansion rate. Finally, we discuss how these effects increase the passage time of surfactant-laden drops in the constriction. |
| Databáze: | OpenAIRE |
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