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arXiv · 0810.2627

Active and Nonlinear Microrheology in Dense Colloidal Suspensions

I. Gazuz·A. M. Puertas·Th. Voigtmann·M. Fuchs
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Abstract

We present a first-principles theory for the active nonlinear microrheology of colloidal model systems: for constant external force on a spherical probe particle embedded in a dense host dispersion, neglecting hydrodynamic interactions, we derive an exact expression for the friction. Within mode-coupling theory (MCT), we discuss the threshold external force needed to delocalize the probe from a host glass, and its relation to strong nonlinear velocity-force curves in a host fluid. Experimental microrheology data and simulations, which we performed, are explained with a simplified model.

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I. Gazuz, A. M. Puertas, Th. Voigtmann, M. Fuchs. 2008-10-15. Active and Nonlinear Microrheology in Dense Colloidal Suspensions. https://doi.org/10.1103/physrevlett.102.248302

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