Laboratoire Charles Coulomb UMR 5221 CNRS/UM2 (L2C)

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Accueil > La Recherche > Axes & Equipes > Matière Molle & Verres > Equipe : Matière Molle > Thème : Interfaces complexes

Off-Equilibrium miscible fluid Interfaces

par Antonio STOCCO - publié le , mis à jour le

Off-Equilibrium miscible fluid Interfaces
People involved : D. Truzzolillo, S. Mora, L. Cipelletti

Interfacial tension between immiscible phases is a well-known phenomenon, which manifests itself in everyday life, from the shape of droplets and foam bubbles, to the capillary rise of sap in plants or the locomotion of insects on a water surface. More than a century ago, D. Korteweg generalized this notion by arguing that stresses at the interface between two miscible fluids act transiently as an effective, non-equilibrium interfacial tension, before homogenization is eventually reached (Figure 1). In spite of its relevance in fields as diverse as geosciences, polymer physics, multiphase flows and fluid removal, experiments and theoretical works on the interfacial tension of miscible systems are still scarce, and mostly restricted to molecular fluids [1]. This leaves crucial questions unanswered, concerning the very existence of the effective interfacial tension, its stabilizing or destabilizing character, and its dependence on the fluids composition and concentration gradients. Our experimental research exploits the direct visualization of hydrodynamic instabilities like radial viscous fingering (Figure 2) to measure interfacial stresses in miscible fluids with particular attention to colloidal and polymeric fluids [2,3,4]. Theoretical work is also currently devoted to a new general thermodynamic formulation for Korteweg stresses.

References :

  • [1] D. Truzzolillo and L. Cipelletti, Soft Matter, - Minireview (2016)
  • [2] D. Truzzolillo, S. Mora, C. Dupas, L. Cipelletti, Phys. Rev. Lett., 112, 208303 (2014)
  • [3] D. Truzzolillo, V. Roger, C. Dupas, S. Mora, L. Cipelletti, J. Phys. : Condens. Matter, 27(19), 194103 (2015).
  • [4] D. Truzzolillo, S. Mora, C. Dupas, and L. Cipelletti. Phys. Rev. X (Submitted - Under review).

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