An approximate analytical expression for the current potential characteristic for charge transfer at a microdisc interface under steady state conditions is given for reversible, quasireversible and irreversible kinetics. The quasireversible expression is proposed as a simple means for analysis of experimental voltammograms thus gaining access to the potential dependent forward rate constant and the charge transfer coefficient, α. It is used to analyse simulated data and the results compared to the simulation parameters. The mathematics of the linear diffusion of cyclic voltammetry for electron transfer at the Interface between Two Immiscible Electrolyte Solutions (ITIES) is addressed, and the numerical solution of the resulting integral equation is evaluated. The results show how the cyclic voltammograms for reversible electron transfer at the ITIES vary when different ratios of reactants and products are used, and how these differ from the classical reversible cyclic voltammograms. A microhole formed by eximer laser ablation in a polyester membrane is proposed as a useful support for a micro-ITIES providing symmetrical diffusion characteristics analogous to an inlaid disc electrode. This support (and also regular arrays of microholes) has been used to obtain symmetrical steady state voltammograms for the transfer of the acetylcholine cation from water to 1,2-dichloroethane. A micro-ITIES suported at the tip of a micropipette has been used to study the transfer of alkali metal ions assisted by crown ethers which gave a lower limit for the pseudo first order interfacial transfer rate constants of 10^-2 cm s^-1, and provided data on the complexation constants of Li^+ , Na^+ , K^+ Rb^+ and Cs^+ with dibenzo-18-crown-6. The oxidations of di-n-butylferrocene and ferrocene by hexacyanoferrate III at the ITIES were investigated using both microinterfaces supported at the tip of a micropipette, and large interfaces.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:642529 |
| Date | January 1991 |
| Creators | Campbell, J. A. |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/13298 |
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