Marangoni flows.
| When |
Apr 25, 2016
from 11:00 to 12:00 |
|---|---|
| Where | Amphi. Schrödinger |
| Attendees |
Isabelle Cantat |
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Surfactant distribution heterogeneities at a fluid/fluid interface trigger the Marangoni effect, i.e. a bulk flow due to a surface tension gradient. These flows are important at small scale, for exemple to control bubble or drop motion, or flows in diphasic medium. In the case of surfactant-induced Marangoni flows, surfactant solubility leads to coupled problems involving hydrodynamics, diffusive and convective transport and free interfaces. In this talk, I will focus on the flow induced by the steady injection of hydrosoluble surfactants at a flat air/water interface. This flow has a finite extension that increases with a decrease of the critical micelle concentration of the surfactants. Scaling laws based on the boundary layer theory captures the flow features and allow to predict the flow extension as a function of the physico-chemical properties of the surfactants.