Overlimiting current through ion concentration polarization layer: hydrodynamic convection effects

In this work, we experimentally investigated an effect of the hydrodynamic convective flow on ion transport through a nanoporous membrane in a micro/nanofluidic modeled system. The convective motion of ions in an ion concentration polarization (ICP) layer was controlled by external hydrodynamic infl...

Full description

Saved in:
Bibliographic Details
Published in:Nanoscale 2014-05, Vol.6 (9), p.4620-4626
Main Authors: Cho, Inhee, Sung, Gun Yong, Kim, Sung Jae
Format: Article
Language:English
Subjects:
Computational fluid dynamics
Convective flow
Fluid flow
Hydrodynamics
Inductively coupled plasma
Membranes
Nanostructure
Polarization
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:In this work, we experimentally investigated an effect of the hydrodynamic convective flow on ion transport through a nanoporous membrane in a micro/nanofluidic modeled system. The convective motion of ions in an ion concentration polarization (ICP) layer was controlled by external hydrodynamic inflows adjacent to the nanoporous membrane. The ion depletion region, which is regarded as a high electrical resistance, was spatially confined to a triangular shape with the additional hydrodynamic convective flow, resulting in a significant alteration in the classical ohmic-limiting-overlimiting current characteristics. Furthermore, the extreme spatial confinement can completely eliminate the limiting current region at a higher flow rate, while the ICP layer still exists. The presented results enable one to obtain a high current value which turns out to be a high electrical power efficiency. Therefore, this mechanism could be utilized as an optimizing power consumption strategy for various electrochemical membrane systems such as fuel-cells, electro-desalination systems and nanofluidic preconcentrators, etc.
ISSN:2040-3364
2040-3372
DOI:10.1039/c3nr04961b