Volume 80, Number 2, October 2007
Article Number 28003
Number of page(s) 5
Section Interdisciplinary Physics and Related Areas of Science and Technology
Published online 14 September 2007
EPL, 80 (2007) 28003
DOI: 10.1209/0295-5075/80/28003

Coarse graining of slow variables in dynamic simulations of soft matter

A. van den Noort, W. K. den Otter and W. J. Briels

Computational Biophysics, Faculty of Science and Technology, University of Twente P.O. Box 217, 7500 AE Enschede, The Netherlands

received 23 March 2007; accepted in final form 21 August 2007; published October 2007
published online 14 September 2007

A new Brownian dynamics model is presented to describe the coarse grain dynamics of particles with long-lived memory. Instead of solving a set of generalized Langevin equations we introduce a set of variables describing the slowly fluctuating thermodynamic state of the ignored degrees of freedom. These variables give rise to additional transient forces on the simulated particles, whose interpretation provides a new way of thinking about memory effects in soft-matter physics. We illustrate the proposed method by simulating shear thinning of synthetic resins.

83.10.Mj - Molecular dynamics, Brownian dynamics.
83.60.Rs - Shear rate-dependent structure (shear thinning and shear thickening).
83.80.Hj - Suspensions, dispersions, pastes, slurries, colloids.

© Europhysics Letters Association 2007