Double step potential chronocoulometric measurements have been set up for the investigation of kinetics of charge transfer across the liquid/liquid interface and to study adsorption at these interfaces. Semioperation analysis of chronoamperometric and chronocoulometric data were also developed and used to evaluate the kinetic parameters. The transfer of the acetylcholine ion across the water/1,2-dichloro-methane, and water/1,2-dichlorobenzene interfaces have been studied as a function of the viscosity of both phases and the composition of the organic phases respectively. The results showed that the standard rate constant is inversely porportional to the viscosity of either phase. The potential dependence of the rate of ion transfer follows the Butler-Volmer equation. It is shown that the main difference between ion transfer and ion transport is a consequence of an entropy effect. The kinetics and thermodynamics of sodium and potassium transfer facilitated by dibenzo-18-crown-6 have been studied by chronocoulometry and its convolution technique and cyclic voltammetry. Three possible mechanisms have been examined carefully and a new terminology is being proposed. A simple way to measure the ratio of the diffusion coefficients of ionophore and its complex ion in the organic phase by using micropipette has been developed. Lithium and proton transfer across water/1,2-dichloro-ethane interface facilitated by ETH1810 have been studied and a mechanism has been proposed. Potassium transfer across water/1,2-dichloro-ethane interface facilitated by DLADB18C6 has also been observed. The adsorption of hexadecyl sulphonate anion (HDS) on the water/1,2-dichloroethane interface has been investigated by classical methodology. Finally, a new method to measure the half wave potential has been applied to the measurement of formal Gibbs energies of transfer of ions across the water/1,2-dichloroethane interface. The validity of TATB (Tetraphenyl-arsonium Tetraphenylborate) assumption is also discussed.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:661781 |
| Date | January 1991 |
| Creators | Shao, Yuanhua |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/14385 |
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