Ref HAL: hal-00966355_v1
DOI: 10.1103/PhysRevLett.112.128303
WoS: 000333917400012
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26 Citations
Résumé:

We study the fingering instability of the interface between two miscible fluids, a colloidal suspension and its own solvent. The temporal evolution of the interface in a Hele-Shaw cell is found to be governed by the competition between the nonlinear viscosity of the suspension and an off-equilibrium, effective surface tension Γe. By studying suspensions in a wide range of volume fractions, Φ, we show that Γe∼Φ^2, in agreement with Korteweg's theory for miscible fluids. The surface tension exhibits an anomalous increase with particle size, which we account for using entropy arguments.