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Enhanced diffusion in soft-walled channels with a periodically varying curvature.

Accepted version
Peer-reviewed

Type

Article

Change log

Authors

Gray, Thomas H 
Castelnovo, Claudio  ORCID logo  https://orcid.org/0000-0003-1752-6343
Yong, Ee Hou 

Abstract

The motion of particles along channels of finite width is known to be hindered by either the presence of energy barriers along the channel direction or by variations in the width of the channel in the transverse direction (rugged channel). Remarkably, when both features are present, they can interact to produce a counterintuitive result: adding energy barriers to a rugged channel can enhance the rate of diffusion along it. This is the result of competing energetic and entropic effects. Under the approximation of particles instantaneously in equilibrium in the transverse direction, one can tailor the energy barriers to the ruggedness to recover free diffusion. However, such fine-tuning and potentially restrictive approximations are not necessary to observe an enhanced rate of diffusion as we demonstrate by adding a range of (non-fine-tuned) energy barriers to a channel of sinusoidally varying curvature. Furthermore, this was observed to hold for systems with a finite characteristic timescale for motion in the transverse direction, thus, suggesting that the phenomenon lends itself to be exploited for practical applications.

Description

Keywords

cond-mat.stat-mech, cond-mat.stat-mech, cond-mat.soft

Journal Title

Phys Rev E

Conference Name

Journal ISSN

2470-0045
2470-0053

Volume Title

105

Publisher

American Physical Society (APS)
Sponsorship
Engineering and Physical Sciences Research Council (EP/P034616/1)
EPSRC (EP/T028580/1)