Journal
EPL
Volume 93, Issue 5, Pages -Publisher
IOP PUBLISHING LTD
DOI: 10.1209/0295-5075/93/58007
Keywords
-
Categories
Funding
- Junta de Andalucia [P09-FQM-4938]
- EPSRC [EP/D071070/1]
- EPSRC [EP/D071070/1, EP/E030173/1] Funding Source: UKRI
- Engineering and Physical Sciences Research Council [EP/E030173/1, EP/D071070/1] Funding Source: researchfish
Ask authors/readers for more resources
We present experiments and computer simulations of a tracer (or probe) particle trapped with optical tweezers and dragged at constant speed through a bath of effectively hard colloids with approximately the same size as the probe. The results are analyzed taking the single-particle case and assuming effective parameters for the bath. The effective microscopic friction coefficient and effective temperature of the tracer are obtained. At high probe velocities, the experimental microviscosity compares well with the viscosity from bulk rheology, whereas a correction due to hydrodynamic interactions (absent in the simulations) is necessary to collapse the simulation data. Surprisingly, agreement is found without any need of hydrodynamic corrections at small probe velocities. The dynamics of the tracer inside the trap shows, both in the simulations and experiments, a fast relaxation due to solvent friction and a slow one caused by the collisions with other particles. The latter is less effective in dissipating the energy introduced by the moving trap and causes increasing fluctuations in the tracer motion, reflected as higher effective temperature. Copyright (C) EPLA, 2011
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available