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Published November 21, 2012 | public
Journal Article

Transient dynamics in dense colloidal suspensions under shear: shear rate dependence

Abstract

A combination of confocal microscopy and rheology experiments, Brownian dynamics (BD) and molecular dynamics (MD) simulations and mode coupling theory (MCT) have been applied in order to investigate the effect of shear rate on the transient dynamics and stress–strain relations in supercooled and glassy systems under shear. Immediately after shear is switched on, the microscopic dynamics display super-diffusion and the macroscopic rheology a stress overshoot, which become more pronounced with increasing shear rate. MCT relates both to negative sections of the generalized shear modulus, which grow with increasing shear rate. When the inverse shear rate becomes much smaller than the structural relaxation time of the quiescent system, relaxation through Brownian motion becomes less important. In this regime, larger stresses are accumulated before the system yields and the transition from localization to flow occurs earlier and more abruptly.

Additional Information

© 2012 Institute of Physics Publishing Ltd. Received 26 April 2012, in final form 22 May 2012. Published 31 October 2012. This work was funded by the Deutsche Forschungsgemeinschaft (DFG) within the German–Dutch Collaborative Research Centre Sonderforschungsbereich-Transregio 6 (SFB-TR6), Project A6. KJM wishes to thank the Alexander von Humboldt Foundation for financial support through a Research Fellowship. GP and NK acknowledge funding by the Greek General Secretariat for Research and Technology (PENED, -03ED566), the EU Network of Excellence Softcomp and the EU FP7 project 'Nanodirect'. The Crete–Caltech collaboration on BD simulations was funded by EU ToK 'Cosines'. We finally thank Th Voigtmann for stimulating discussions.

Additional details

Created:
August 19, 2023
Modified:
October 20, 2023