Yield-stress transition in suspensions of deformable droplets

Abstract

Yield-stress materials, which require a sufficiently large forcing to flow, are currently ill-understood theoretically. To gain insight into their yielding transition, here we study numerically the rheology of a suspension of deformable droplets under pressure-driven flow. We show that the suspension displays yield-stress behaviour, with the droplets remaining motionless when the applied body-force is below a critical value. In the non-flowing phase, droplets jam to form an amorphous structure, whereas they order in the flowing phase. Yielding is linked to a percolation transition in the contacts of droplet-droplet overlaps, and requires suitable wetting boundary conditions and strict conservation of the droplet area to exist. Close to the yielding transition, we find strong oscillations in the droplet motion which closely resemble those found experimentally in confined colloidal glasses under flow. We show that even when droplets are static the underlying solvent moves by permeation, so that the viscosity of the composite system is never truly infinite, and, as we discuss, its precise value ceases to be a bulk material property of the system.

References in corpus (27)

• Rheology of Soft Glassy Materials
• Yield Stress Materials in Soft Condensed Matter
• Motility-driven glass and jamming transitions in biological tissues
• The Physics of the Colloidal Glass Transition
• Discontinuous shear thickening without inertia in dense non-Brownian suspensions
• Steady-state hydrodynamic instabilities of active liquid crystals: Hybrid lattice Boltzmann simulations
• In Search of Colloidal Hard Spheres
• Hard Spheres: Crystallization and Glass Formation
• Theories of Binary Fluid Mixtures: From Phase-Separation Kinetics to Active Emulsions
• Shear zones and wall slip in the capillary flow of concentrated colloidal suspensions
• The microscopic role of deformation in the dynamics of soft colloids
• Solid-Liquid Transition of Deformable and Overlapping Active Particles
• Lattice Boltzmann Methods and Active Fluids
• Velocity oscillations in confined channel flows of concentrated colloidal suspensions
• Hybrid lattice Boltzmann model for binary fluid mixtures
• Flow in linearly sheared two dimensional foams: from bubble to bulk scale
• Nonlinear Stress Fluctuation Dynamics of Sheared Disordered Wet Foam
• Flow of deformable droplets: discontinuous shear thinning and velocity oscillations
• Jamming transitions in a schematic model of suspension rheology
• Rheology of active polar emulsions: from linear to unidirectional and unviscid flow, and intermittent viscosity
• Tuning the rheological behavior of colloidal gels through competing interactions
• Soft channel formation and symmetry breaking in exotic active emulsions
• Discrete fluidization of dense monodisperse emulsions in neutral wetting microchannels
• Concentrated phase emulsion with multi-core morphology under shear: A numerical study
• Comparison between isothermal collision-streaming and finite-difference lattice Boltzmann models
• Rheology of active emulsions with negative effective viscosity
• Mixtures of blue phase liquid crystal with simple liquids: elastic emulsions and cubic fluid cylinders

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• Rheology of Two-Dimensional Dilute Emulsions