Related Experiment Video
Updated: Jul 13, 2026

Generation and Control of Electrohydrodynamic Flows in Aqueous Electrolyte Solutions
Published on: September 7, 2018
Comparison of the Nernst-Planck model and the Poisson-Boltzmann model for electroosmotic flows in microchannels
1Department of Chemical and Biomolecular Engineering, Sogang University, Seoul, South Korea. hmpark@sogang.ac.kr
Abstract:
In the analysis of electroosmotic flows, the internal electric potential is usually modeled by the Poisson-Boltzmann equation. The Poisson-Boltzmann equation is derived from the assumption of thermodynamic equilibrium where the ionic distributions are not affected by fluid flows. Although this is a reasonable assumption for steady electroosmotic flows through straight microchannels, there are some important cases where convective transport of ions has nontrivial effects. In these cases, it is necessary to adopt the Nernst-Planck equation instead of the Poisson-Boltzmann equation to model the internal electric field. In the present work, the predictions of the Nernst-Planck equation are compared with those of the Poisson-Boltzmann equation for electroosmotic flows in various microchannels where the convective transport of ions is not negligible.
Related Concept Videos
The Electrical Double Layer
Poisson's And Laplace's Equation
Processes at Electrodes
Steady, Laminar Flow in Circular Tubes
Steady, Laminar Flow Between Parallel Plates
Debye–Huckel–Onsager Conductance Equation

