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arXiv · 0807.3925

From Equilibrium to Steady State: The Transient Dynamics of Colloidal Liquids under Shear

J. Zausch·J. Horbach·M Laurati·S. U. Egelhaaf·J. M. Brader·Th. Voigtmann·M. Fuchs
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Abstract

We investigate stresses and particle motion during the start up of flow in a colloidal dispersion close to arrest into a glassy state. A combination of molecular dynamics simulation, mode coupling theory and confocal microscopy experiment is used to investigate the origins of the widely observed stress overshoot and (previously not reported) super-diffusive motion in the transient dynamics. A link between the macro-rheological stress versus strain curves and the microscopic particle motion is established. Negative correlations in the transient auto-correlation function of the potential stresses are found responsible for both phenomena, and arise even for homogeneous flows and almost Gaussian particle displacements.

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J. Zausch, J. Horbach, M Laurati, S. U. Egelhaaf, J. M. Brader, Th. Voigtmann, M. Fuchs. 2008-07-24. From Equilibrium to Steady State: The Transient Dynamics of Colloidal Liquids under Shear. https://doi.org/10.1088/0953-8984%2F20%2F40%2F404210

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