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Colloid-colloid hydrodynamic interaction around a bend in a quasi-one-dimensional channel
Christopher Liepold1, Ryan Zarcone1, Tibor Heumann1
1James Franck Institute, University of Chicago, Chicago, Illinois 60637, USA.
Physical Review. E
|January 20, 2018
Summary
A bend in a quasi-one-dimensional channel alters colloid suspension dynamics. Particle depletion and altered diffusion near the bend result from boundary conditions forcing single-file motion and flow around the curve.
Area of Science:
- Soft matter physics
- Fluid dynamics
- Colloid science
Background:
- Quasi-one-dimensional (q1D) channels confine particle motion.
- Single-file particle motion is observed in dense colloidal suspensions.
- Hydrodynamic coupling influences particle interactions and diffusion.
Purpose of the Study:
- To investigate the effect of channel bends on hydrodynamic coupling in colloid suspensions.
- To analyze structural and dynamical responses of particles to varying bend angles.
- To understand how boundary conditions in bent channels influence particle behavior.
Main Methods:
- Simulating colloid suspension in a q1D channel with varying bend angles.
- Analyzing structural changes using pair correlation functions.
- Quantifying dynamical responses via self-diffusion (D11) and coupling (D12) terms of the pair diffusion tensor.
Main Results:
- Observed particle depletion near the bend and increased nearest-neighbor separation.
- The pair separation dependence of the coupling term (D12) mirrors the pair correlation function.
- Structural and dynamical responses intensify with more acute bend angles.
Conclusions:
- Channel bends significantly impact hydrodynamic coupling in q1D colloid suspensions.
- Observed phenomena are attributed to boundary conditions enforcing adherence to the channel's geometry.
- Single-file motion and hydrodynamic flow adapt to the channel's curvature.
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