This paper computes the electrostatic force on a cylindrical colloidal particle when it is in the proximity of a charged planar wall and an external electric field parallel to the planar wall is applied. The electrostatic force depends on the electric field distribution around the particle and is calculated by integrating the electrostatic stress tensor over the particle surface. The electric field, as well as the ion distribution, is obtained from the numerical solution of Poisson-Nernst-Planck equations on Chimera grids by using the finite-volume method. A comparison of the electrostatic force obtained from the Poisson-Nernst-Planck model and with that obtained from the Poisson-Boltzmann model has been made to identify the limitations of the Poisson-Boltzmann model. The Poisson-Boltzmann model is found not to account for the effect of an external field on the distribution of ions and hence to predict a high electrostatic force in the direction of the external electric field.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)