Charge transfer across liquid/liquid interfaces : theory and applications

• Main Author: Beattie, Paul Daniel
• Published: University of Edinburgh 1995
• Subjects: 530.0724
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.641426

This thesis is concerned with charge transfer processes at the interface between two immiscible electrolyte solutions (ITIES), from both a kinetic and analytical viewpoint. Microholes, formed by ultra-violet excimer laser photoablation of polyester films, and micropipettes, fabricated from borosilicate glass capillaries by means of a pipette puller, are both used to support the ITIES for the study of ion and assisted ion transfer reactions respectively. Using the techniques of steady-state voltammetry and a.c. impedance, both processes are found to be dependent on diffusion of the participating species to the interface only. Electron transfer reactions at the ITIES are studied using cyclic voltammetry. Transfer between the hexacyanoferrate redox couple ([Fe(CN)<SUB>6</SUB>]<SUP>3-/4-</SUP>) in the aqueous phase, and ferrocene and 1,1'-dimethylferrocene, respectively, in the organic (1,2-DCE) phase, is investigated. Results obtained for transfer between copper (II) ions in the aqueous phase and ferrocene in 1,2-DCE are also presented. An investigation is made into the inhibition of the enzyme butyrylcholinesterase by the organophosphate compound paraoxon (diethyl <I>p</I>-nitrophenyl phosphate), using butyrylcholine chloride as the substrate. Experimental measurement is based on the transfer of the butyrylcholine cation across the ITIES. By this method it is possible to determine the rate constants for both the inhibition of the enzyme and the hydrolysis of butyrylcholine.