Nonlinear ion transport mediated by induced charge in ultrathin nanoporous membranes
Name
PhysRevE.104.044802.pdf
Description
Published version
Size
2.69 MB
Format
Unknown
Checksum (MD5)
75bc9d42f2f1ee2a7b00ad345f5cd3e7
Author(s)
de Souza, J Pedro
Chow, Chun-Man
Karnik, Rohit
Bazant, Martin Z
Date Issued
October 2021
Journal
Physical Review E
Publisher
American Physical Society (APS)
Citation
de Souza, J Pedro, Chow, Chun-Man, Karnik, Rohit and Bazant, Martin Z. 2021. "Nonlinear ion transport mediated by induced charge in ultrathin nanoporous membranes." Physical Review E, 104 (4).
Version
Final published version
Abstract
Ultrathin membranes with nanoporous conduits show promise for ionic separations and desalination applications, but the mechanisms underlying the nonlinear ionic transport observed in these systems are not well understood. Here, we demonstrate how induced charge at membrane interfaces can lead to nonlinear ionic transport and voltage-dependent conductance through such channels. The application of an electric field on a polarizable membrane leads to induced charges at the membrane interfaces. The induced charges in turn are screened by diffuse charges in the electrolyte, which are acted upon by the electric field. For extremely thin membranes, the induced charge effect can be significant even for moderate applied voltages commonly used in experiments. We apply a continuum Poisson-Nernst-Planck model to characterize the current-voltage behavior of ultrathin membranes over a wide parameter space. The predictions of the model are compared to recent experiments on graphene and MoS_{2} membranes in an electric field. We expect the role of induced charge to be especially pronounced in the limit of atomically thin membranes.
MIT Department
Massachusetts Institute of Technology. Department of Chemical Engineering
Massachusetts Institute of Technology. Department of Mechanical Engineering
Massachusetts Institute of Technology. Department of Mathematics
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Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
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DOI of Published Version
https://doi.org/10.1103/physreve.104.044802
