Showing papers by "Barry Miller published in 1970"

An Experimental Study of Nonuniform Current Distribution at Rotating Disk Electrodes

Abstract: The theoretical predictions of Newman (1, 2) concerning the existence of a nonuniform current distribution at rotating disk electrodes have been verified in media containing insufficient supporting electrolyte. Measurements of the thickness of copper films deposited on a platinum disk yield results qualitatively of the form predicted by Newman. The primary current distribution is approached at currents corresponding to a small fraction of the limiting convective diffusion current in the absence of appreciable supporting electrolyte, while a uniform current distribution is found in the limiting current region. Nonuniform current distribution at a disk electrode has been found to have significant effects on the collection efficiency of a ring‐disk electrode. These effects depend markedly on the geometry of the electrode. Similar behavior has been noted in the currents observed at "shielded" rings of ring‐disk electrodes. Under conventional polarographic conditions in solutions containing fifty‐ to a hundred‐fold excess of supporting electrolyte, no significant deviations from a uniform disk current distribution could be detected.