Superposition rheology of shear-banding wormlike micelles

Abstract

Wormlike micelle solutions are submitted to small-amplitude oscillatory shear superimposed to steady shear in the shear banding regime. By imposing a shear oscillation, the interface between high- and low-shear regions oscillates in time. A two-fluid semi-phenomenological model is proposed for superposition rheology in the shear banding regime, which allows us to extract a characteristic velocity for the interface dynamics from experiments involving only a standard rheometer. Estimates of the stress diffusion coefficient $\mathcal{D}$ can also be inferred from such superposition experiments. The validity of our model is confirmed by directly recording the interface displacement using ultrasonic velocimetry.

arXiv comment24 pages, 13 figures

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Cited by in corpus (6)

• Shear Banding of Complex Fluids
• Recent experimental probes of shear banding
• Shear-induced transitions and instabilities in surfactant wormlike micelles
• Elastic turbulence in shear banding wormlike micelles
• Non-axisymmetric instability of shear-banded Taylor-Couette flow
• Surfactant micelles: model systems for flow instabilities of complex fluids