Nernst–Planck modeling of multicomponent ion transport in a Nafion membrane at high current density
| Autor: | Jos T. F. Keurentjes, N. A. W. Oppers, JC Jaap Schouten, M.T. de Groot, J. van der Schaaf, S. Moshtarikhah |
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| Přispěvatelé: | Chemical Reactor Engineering |
| Rok vydání: | 2016 |
| Předmět: |
General Chemical Engineering
Thermodynamics Nanotechnology 02 engineering and technology 010402 general chemistry 01 natural sciences Ion Quantitative Biology::Subcellular Processes symbols.namesake Potential gradient Membrane selectivity Materials Chemistry Electrochemistry Nernst equation Ion transporter Membrane potential Physics::Biological Physics Chemistry Drop (liquid) Nernst–Planck Membrane resistivity 021001 nanoscience & nanotechnology 0104 chemical sciences Membrane High current density Multicomponent ion transport Chemical Engineering(all) symbols 0210 nano-technology Current density |
| Zdroj: | Journal of Applied Electrochemistry, 47(1), 51-62. Springer |
| ISSN: | 1572-8838 0021-891X |
| DOI: | 10.1007/s10800-016-1017-2 |
| Popis: | A mathematical model of multicomponent ion transport through a cation-exchange membrane is developed based on the Nernst–Planck equation. A correlation for the non-linear potential gradient is derived from current density relation with fluxes. The boundary conditions are determined with the Donnan equilibrium at the membrane–solution interface, taking into account the convective flow. Effective diffusivities are used in the model based on the correlation of tortuosity and ionic diffusivities in free water. The model predicts the effect of an increase in current density on the ion concentrations inside the membrane. The model is fitted to the previously published experimental data. The effect of current density on the observed increase in voltage drop and the decrease in permselectivity has been analyzed using the available qualitative membrane swelling theories. The observed non-linear behavior of the membrane voltage drop versus current density can be explained by an increase in membrane pore diameter and an increase in the number of active pores. We show how the membrane pore diameter increases and dead-end pores open up when the current density is increased. |
| Databáze: | OpenAIRE |
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