Molecular Dynamics Simulations of Ion Drift in Nanochannel Water Flow
1
Physics Department, University of Thessaly, 35100 Lamia, Greece
2
Department of Mechanical Engineering, University of West Attica, 12244 Athens, Greece
*
Author to whom correspondence should be addressed.
Nanomaterials 2020, 10(12), 2373; https://doi.org/10.3390/nano10122373
Received: 30 October 2020
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Revised: 25 November 2020
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Accepted: 25 November 2020
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Published: 28 November 2020
The present paper employs Molecular Dynamics (MD) simulations to reveal nanoscale ion separation from water/ion flows under an external electric field in Poiseuille-like nanochannels. Ions are drifted to the sidewalls due to the effect of wall-normal applied electric fields while flowing inside the channel. Fresh water is obtained from the channel centerline, while ions are rejected near the walls, similar to the Capacitive DeIonization (CDI) principles. Parameters affecting the separation process, i.e., simulation duration, percentage of the removal, volumetric flow rate, and the length of the nanochannel incorporated, are affected by the electric field magnitude, ion correlations, and channel height. For the range of channels investigated here, an ion removal percentage near 100% is achieved in most cases in less than 20 ns for an electric field magnitude of E = 2.0 V/Å. In the nutshell, the ion drift is found satisfactory in the proposed nanoscale method, and it is exploited in a practical, small-scale system. Theoretical investigation from this work can be projected for systems at larger scales to perform fundamental yet elusive studies on water/ion separation issues at the nanoscale and, one step further, for designing real devices as well. The advantages over existing methods refer to the ease of implementation, low cost, and energy consumption, without the need to confront membrane fouling problems and complex electrode material fabrication employed in CDI.
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Keywords:
nanochannel flows; electric field; ion separation; molecular dynamics
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MDPI and ACS Style
Sofos, F.; Karakasidis, T.; Sarris, I.E. Molecular Dynamics Simulations of Ion Drift in Nanochannel Water Flow. Nanomaterials 2020, 10, 2373. https://doi.org/10.3390/nano10122373
AMA Style
Sofos F, Karakasidis T, Sarris IE. Molecular Dynamics Simulations of Ion Drift in Nanochannel Water Flow. Nanomaterials. 2020; 10(12):2373. https://doi.org/10.3390/nano10122373
Chicago/Turabian StyleSofos, Filippos, Theodoros Karakasidis, and Ioannis E. Sarris. 2020. "Molecular Dynamics Simulations of Ion Drift in Nanochannel Water Flow" Nanomaterials 10, no. 12: 2373. https://doi.org/10.3390/nano10122373
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