Driven colloidal fluids: construction of dynamical density functional theories from exactly solvable limits

Scacchi, Alberto; Krüger, Matthias; Brader, Joseph M.

doi:10.1088/0953-8984/28/24/244023

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Journal article

Driven colloidal fluids: construction of dynamical density functional theories from exactly solvable limits

Scacchi, Alberto Department of Physics, University of Fribourg, CH-1700 Fribourg, Switzerland
Krüger, Matthias 4th Institute for Theoretical Physics, Universität Stuttgart, and Max Planck Institute for Intelligent Systems, Stuttgart, Germany
Brader, Joseph M. Department of Physics, University of Fribourg, CH-1700 Fribourg, Switzerland

26.04.2016

Published in:

Journal of Physics: Condensed Matter. - 2016, vol. 28, no. 24, p. 244023

English The classical dynamical density functional theory (DDFT) provides an approximate extension of equilibrium DFT to treat nonequilibrium systems subject to Brownian dynamics. However, the method fails when applied to driven systems, such as sheared colloidal dispersions. The breakdown of DDFT can be traced back to an inadequate treatment of the flow-induced distortion of the pair correlation functions. By considering the distortion of the pair correlations to second order in the flow-rate we show how to systematically correct the DDFT for driven systems. As an application of our approach we consider Poiseuille flow. The theory predicts that the particles will accumulate in spatial regions where the local shear rate is small, an effect known as shear-induced migration. We compare these predictions to Brownian dynamics simulations with generally good agreement.

Faculty

Faculté des sciences et de médecine

Department

Département de Physique

Language