TY - JOUR

T1 - Unified theoretical and experimental view on transient shear banding

AU - Benzi, Roberto

AU - Divoux, Thibaut

AU - Barentin, Catherine

AU - Manneville, Sébastien

AU - Sbragaglia, Mauro

AU - Toschi, Federico

PY - 2019/12/9

Y1 - 2019/12/9

N2 - Dense emulsions, colloidal gels, microgels, and foams all display a solidlike behavior at rest characterized by a yield stress, above which the material flows like a liquid. Such a fluidization transition often consists of long-lasting transient flows that involve shear-banded velocity profiles. The characteristic time for full fluidization τf has been reported to decay as a power law of the shear rate γ and of the shear stress σ with respective exponents α and β. Strikingly, the ratio of these exponents was empirically observed to coincide with the exponent of the Herschel-Bulkley law that describes the steady-state flow behavior of these complex fluids. Here we introduce a continuum model, based on the minimization of a "free energy," that captures quantitatively all the salient features associated with such transient shear banding. More generally, our results provide a unified theoretical framework for describing the yielding transition and the steady-state flow properties of yield stress fluids.

AB - Dense emulsions, colloidal gels, microgels, and foams all display a solidlike behavior at rest characterized by a yield stress, above which the material flows like a liquid. Such a fluidization transition often consists of long-lasting transient flows that involve shear-banded velocity profiles. The characteristic time for full fluidization τf has been reported to decay as a power law of the shear rate γ and of the shear stress σ with respective exponents α and β. Strikingly, the ratio of these exponents was empirically observed to coincide with the exponent of the Herschel-Bulkley law that describes the steady-state flow behavior of these complex fluids. Here we introduce a continuum model, based on the minimization of a "free energy," that captures quantitatively all the salient features associated with such transient shear banding. More generally, our results provide a unified theoretical framework for describing the yielding transition and the steady-state flow properties of yield stress fluids.

UR - http://www.scopus.com/inward/record.url?scp=85076520555&partnerID=8YFLogxK

U2 - 10.1103/PhysRevLett.123.248001

DO - 10.1103/PhysRevLett.123.248001

M3 - Article

C2 - 31922825

VL - 123

JO - Physical Review Letters

JF - Physical Review Letters

SN - 0031-9007

IS - 24

M1 - 248001

ER -