Viscous fingering at ultralow interfacial tension

Abstract

We experimentally study the viscous fingering instability in a fluid-fluid phase separated colloid-polymer mixture by means of laser scanning confocal microscopy and microfluidics. We focus on three aspects of the instability. (i) The interface between the two demixed phases has an ultralow surface tension, such that we can address the role of thermal interface fluctuations. (ii) We image the interface in three dimensions allowing us to study the interplay between interface curvature and flow. (iii) The displacing fluid wets all walls completely, in contrast to traditional viscous fingering experiments, in which the displaced fluid wets the walls. We also perform lattice Boltzmann simulations, which help to interpret the experimental observations.

References in corpus (2)

• Three-dimensional aspects of fluid flows in channels. I. Meniscus and Thin Film regimes
• Three-dimensional aspects of fluid flows in channels. II. Effects of Meniscus and Thin Film regimes on Viscous Fingers

Cited by in corpus (8)

• Fingering versus stability in the limit of zero interfacial tension
• Forced imbibition in porous media: a fourfold scenario
• Revisiting the Saffman-Taylor experiment: imbibition patterns and liquid-entrainment transitions
• Non-negative Interfacial Tension in Phase-Separated Active Brownian Particles
• Manipulation of Viscous Fingering in a Radially-Tapered Cell Geometry
• Off-equilibrium surface tension in colloidal suspensions
• Growth morphology and symmetry selection of interfacial instabilities in anisotropic environments
• Side branched patterns, coalescence and stable interfaces during radial displacement of a viscoelastic fluid