Boundary effects on the bipolar behavior of a spherical particle in an electrolytic cell
Journal
Journal of the Electrochemical Society
Journal Volume
144
Journal Issue
10
Pages
3536-3544
Date Issued
1997
Author(s)
Abstract
A combined analytic and numerical study is presented for the bipolar behavior of a spherical particle in the proximity of a large plane wall. The electric field is exerted in two fundamental cases: normal to a perfectly conducting plane and parallel to a perfectly nonconducting wall. Linearly polarized electrode kinetics is assumed for the electrochemical reaction occurring at the particle surface. The governing equations for the electric potential field applicable to the systems are solved using bispherical coordinates. The current-density distribution and the current-enhancement factor of the particle are determined for various cases. It is found that the current-enhancement factor of the particle can be increased or decreased by the presence of the plane wall, depending on the relative conductivity of the particle with respect to the surrounding electrolytic solution (κ*) and the relative resistance of the reaction arising at the particle surface with respect to the conduction inside the particle (γ). The interaction effects between the wall and the particle can be significant when the gap thickness gets close to zero. For the special case of κ*- γ = 1, the current-density distribution and the current-enhancement factor of the spherical particle are not affected by the presence of the wall.
Type
journal article