Near-wall boundary layers at electrode surfaces studied by attenuated total reflection Part I.Mass transfer

Abstract

The local hydrodynamic conditions in the diffusional layer close to an electrode surface have been studied using evanescent field absorption realised in a total internal reflectance mode employing a thin film electrode to generate electrochemically a strongly absorbing radical ion in the solution close to the surface under study. Only a solution depth of the order of a fraction of the wavelength of the light used is monitored. It is shown that the diffusion of the absorbing radical measured optically is in agreement with predictions from dimensionless numbers relationships. The technique can be used for studying near-wall hydrodynamic conditions and deleterious effects of flow on materials.