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Electroviscous effect on fluid drag in a microchannel with large zeta potential

The electroviscous effect has been widely studied to investigate the effect of surface charge-induced electric double layers (EDL) on the pressure-driven flow in a micro/nano channel. EDL has been reported to reduce the velocity of fluid flow and increase the fluid drag. Nevertheless, the study on t...

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Autores principales: Jing, Dalei, Bhushan, Bharat
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Beilstein-Institut 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4685911/
https://www.ncbi.nlm.nih.gov/pubmed/26734512
http://dx.doi.org/10.3762/bjnano.6.226
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author Jing, Dalei
Bhushan, Bharat
author_facet Jing, Dalei
Bhushan, Bharat
author_sort Jing, Dalei
collection PubMed
description The electroviscous effect has been widely studied to investigate the effect of surface charge-induced electric double layers (EDL) on the pressure-driven flow in a micro/nano channel. EDL has been reported to reduce the velocity of fluid flow and increase the fluid drag. Nevertheless, the study on the combined effect of EDL with large zeta potential up to several hundred millivolts and surface charge depenedent-slip on the micro/nano flow is still needed. In this paper, the nonlinear Poisson–Boltzmann equation for electrical potential and ion distribution in non-overlapping EDL is first analytically solved. Then, the modified Navier–Stokes equation for the flow considering the effect of surface charge on the electrical conductivity of the electrolyte and slip length is analytically solved. This analysis is used to study the effect of non-overlapping EDL with large zeta potential on the pressure-driven flow in a microchannel with no-slip and charge-dependent slip conditions. The results show that the EDL leads to an increase in the fluid drag, but that slip can reduce the fluid drag. When the zeta potential is large enough, the electroviscous effect disappears for flow in the microchannel under a no-slip condition. However, the retardation of EDL on the flow and the enhancement of slip on the flow counteract each other under a slip condition. The underlying mechanisms of the effect of EDL with large zeta potential on fluid drag are the high net ionic concentration near the channel wall and the fast decay of electrical potential in the EDL when the zeta potential is large enough.
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spelling pubmed-46859112016-01-05 Electroviscous effect on fluid drag in a microchannel with large zeta potential Jing, Dalei Bhushan, Bharat Beilstein J Nanotechnol Full Research Paper The electroviscous effect has been widely studied to investigate the effect of surface charge-induced electric double layers (EDL) on the pressure-driven flow in a micro/nano channel. EDL has been reported to reduce the velocity of fluid flow and increase the fluid drag. Nevertheless, the study on the combined effect of EDL with large zeta potential up to several hundred millivolts and surface charge depenedent-slip on the micro/nano flow is still needed. In this paper, the nonlinear Poisson–Boltzmann equation for electrical potential and ion distribution in non-overlapping EDL is first analytically solved. Then, the modified Navier–Stokes equation for the flow considering the effect of surface charge on the electrical conductivity of the electrolyte and slip length is analytically solved. This analysis is used to study the effect of non-overlapping EDL with large zeta potential on the pressure-driven flow in a microchannel with no-slip and charge-dependent slip conditions. The results show that the EDL leads to an increase in the fluid drag, but that slip can reduce the fluid drag. When the zeta potential is large enough, the electroviscous effect disappears for flow in the microchannel under a no-slip condition. However, the retardation of EDL on the flow and the enhancement of slip on the flow counteract each other under a slip condition. The underlying mechanisms of the effect of EDL with large zeta potential on fluid drag are the high net ionic concentration near the channel wall and the fast decay of electrical potential in the EDL when the zeta potential is large enough. Beilstein-Institut 2015-11-24 /pmc/articles/PMC4685911/ /pubmed/26734512 http://dx.doi.org/10.3762/bjnano.6.226 Text en Copyright © 2015, Jing and Bhushan https://creativecommons.org/licenses/by/2.0https://www.beilstein-journals.org/bjnano/termsThis is an Open Access article under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The license is subject to the Beilstein Journal of Nanotechnology terms and conditions: (https://www.beilstein-journals.org/bjnano/terms)
spellingShingle Full Research Paper
Jing, Dalei
Bhushan, Bharat
Electroviscous effect on fluid drag in a microchannel with large zeta potential
title Electroviscous effect on fluid drag in a microchannel with large zeta potential
title_full Electroviscous effect on fluid drag in a microchannel with large zeta potential
title_fullStr Electroviscous effect on fluid drag in a microchannel with large zeta potential
title_full_unstemmed Electroviscous effect on fluid drag in a microchannel with large zeta potential
title_short Electroviscous effect on fluid drag in a microchannel with large zeta potential
title_sort electroviscous effect on fluid drag in a microchannel with large zeta potential
topic Full Research Paper
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4685911/
https://www.ncbi.nlm.nih.gov/pubmed/26734512
http://dx.doi.org/10.3762/bjnano.6.226
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