Date of Award
Electrochemical analysis, Diffusion, Twin-electrode thin-layer electrochemistry
Doctor of Philosophy (PhD)
Eugene E. Schrier
Walter E. Kaskan
Science and Mathematics
The method of measuring diffusion coefficients using the twin-electrode thin-layer micrometer cell has been critically evaluated using the ferri-ferrocyanide couple in aqueous KCl as a model system. It has been demonstrated that precise measurements of steady-state currents and coulometric slopes can be made leading to reliable values for diffusion coefficients of soluble redox systems.
The following other systems were studied: Cu(II)/Cu(I) in 0.25M tetraethylallnonium perchlorate(TEAP-acetonitrile medium; ferroceneferricinim in three different solvents (acidified acetonitrile, N,N-dimethylformamide, propylene carbonate) with 0.1M TEAP as supporting electrolyte. Diffusion coefficients for the electroactive species were obtained, and electron-transfer characteristics of the redox systems were observed.
The dependence of the diffusion coefficients on viscosity was found to be in general agreement with the Stokes-Einstein relationship for the systems examined.
The kinetics of the reaction of ferricinium ion with oxygen was studied in a preliminary fashion. A second-order dependence on ferrocene concentration was found, with fractional order of dependence on oxygen.
Konopka, Stanley J., "Diffusion coefficient measurements and other investigations using the methods of twin-electrode thin-layer electrochemistry" (1971). Graduate Dissertations and Theses. 165.