- Author
- Nguyen, T. | Pommersheim, J. M.
- Title
- Diffusion of Cations Along the Polymer/Metal Interface Under an Applied Electrical Potential.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD Bucknell Univ., Lewisburg, PA
- Book or Conf
- Materials Research Society Symposium Proceedings. Volume 304. 1993, 15-20 p., 1993
- Keywords
- diffusion | coatings | sodium | mathematical models | experiments | equations
- Identifiers
- cations; electrolytes
- Abstract
- Diffusion of cations along the polymer/metal interface controls the rate of blistering of polymer coatings on metals exposed to electrolytes. Cations are driven by both concentration and electrical potential gradients. A theoretical and experimental study was carried out on the diffusion of sodium ion along the polymer coating/steel interface under an applied potential. Mathematical models, consisting of initial and propagation stages, are derived based on a moving boundary diffusion problem. Model variables include ion diffusivity, potential grandient and distance between defects and delamination sites. Models are solved to predict ion fluxes and concentration in the blistering areas. Experimental data are analyzed to extract model parameters. Model predictions agreed well with experimental data and practical observations.