https://doi.org/10.1140/epje/i2012-12128-4
Regular Article
Restructuring of colloidal aggregates in shear flow
Coupling interparticle contact models with Stokesian dynamics
1
Chair for Process Systems Engineering, Technische Universität München, Weihenstephaner Steig 23, 85350, Freising, Germany
2
Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
3
Laboratoire de Physique des Solides, Université Paris-Sud, UMR 8502, 91405, Orsay, France
* e-mail: setoryohei@me.com
Received:
25
April
2012
Revised:
26
September
2012
Accepted:
12
November
2012
Published online:
12
December
2012
A method to couple interparticle contact models with Stokesian dynamics (SD) is introduced to simulate colloidal aggregates under flow conditions. The contact model mimics both the elastic and plastic behavior of the cohesive connections between particles within clusters. Owing to this, clusters can maintain their structures under low stress while restructuring or even breakage may occur under sufficiently high stress conditions. SD is an efficient method to deal with the long-ranged and many-body nature of hydrodynamic interactions for low Reynolds number flows. By using such a coupled model, the restructuring of colloidal aggregates under shear flows with stepwise increasing shear rates was studied. Irreversible compaction occurs due to the increase of hydrodynamic stress on clusters. Results show that the greater part of the fractal clusters are compacted to rod-shaped packed structures, while the others show isotropic compaction.
Key words: Soft Matter: Colloids and Nanoparticles
© EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg, 2012