Fluctuation-enhanced electric conductivity in electrolyte solutions
| Autor: | Jean-Philippe M. Péraud, John B. Bell, Aleksandar Donev, Andrew Nonaka, Alejandro L. Garcia |
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| Rok vydání: | 2017 |
| Předmět: |
FOS: Physical sciences
Thermal fluctuations Nernst-Plank equations Nernst–Plank equations 01 natural sciences 010305 fluids & plasmas Navier–Stokes equations fluctuating hydrodynamics Thermal velocity Electrical resistivity and conductivity Electric field 0103 physical sciences multicomponent diffusion Physics::Chemical Physics Diffusion (business) cond-mat.stat-mech 010306 general physics Condensed Matter - Statistical Mechanics Physics Multidisciplinary Statistical Mechanics (cond-mat.stat-mech) Condensed matter physics Fluid Dynamics (physics.flu-dyn) Physics - Fluid Dynamics physics.flu-dyn Physical Sciences Relaxation (physics) Electrohydrodynamics Navier-Stokes equations electrohydrodynamics |
| Zdroj: | Proceedings of the National Academy of Sciences of the United States of America, vol 114, iss 41 Péraud, JP; Nonaka, AJ; Bell, JB; Donev, A; & Garcia, AL. (2017). Fluctuation-enhanced electric conductivity in electrolyte solutions. Proceedings of the National Academy of Sciences of the United States of America, 114(41), 10829-10833. doi: 10.1073/pnas.1714464114. Lawrence Berkeley National Laboratory: Retrieved from: http://www.escholarship.org/uc/item/43p8n2gb |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.1714464114 |
| Popis: | In this letter we analyze the effects of an externally applied electric field on thermal fluctuations for a fluid containing charged species. We show in particular that the fluctuating Poisson-Nernst-Planck equations for charged multispecies diffusion coupled with the fluctuating fluid momentum equation, result in enhanced charge transport. Although this transport is advective in nature, it can macroscopically be represented as electrodiffusion with renormalized electric conductivity. We calculate the renormalized electric conductivity by deriving and integrating the structure factor coefficients of the fluctuating quantities and show that the renormalized electric conductivity and diffusion coefficients are consistent although they originate from different noise terms. In addition, the fluctuating hydrodynamics approach recovers the electrophoretic and relaxation corrections obtained by Debye-Huckel-Onsager theory, and provides a quantitative theory that predicts a non-zero cross-diffusion Maxwell-Stefan coefficient that agrees well with experimental measurements. Finally, we show that strong applied electric fields result in anisotropically enhanced velocity fluctuations and reduced fluctuations of salt concentrations. Comment: 12 pages, 1 figure |
| Databáze: | OpenAIRE |
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