This work details the simulation of charge transfer at ultramicrointerfaces. A novel algorithm is presented for the simulation of electrochemical techniques applied to both ultramicrodisc and ultramicropipette electrodes. <i>Numerical Method</i>. The simulations employ the Crank-Nicolson finite differences or the Alternating Direction Implicit (ADI) method extended to include expansion of the space grid in two dimensions, a n-point current calculation and implicit determination of boundary conditions. The effects are determined of; point separation, choice of grid expansion equation, boundary conditions and relative number of points on electrode and in solution. Also, diffusion geometry, time increment, and the stability of the algorithm are considered in detail. The various methods currently available to model electrochemical response at ultramicrointerfaces are discussed, together with their limitations and a suggested protocol for their use. <i>Computing</i>. All programs are written in FORTRAN and all calculations performed in double precision. Source codes were compiled and run on the Edinburgh Multi-Access System (EMAS). <i>Electrochemical techniques</i>. Techniques simulated include cyclic voltammetry and chronoamperometry at macro, ultramicrodisc and ultramicropipette electrodes, including asymmetric sweep voltammetry at ultramicropipette electrodes. Results are presented for both reversible and quasi-reversible charge transfer. Effects of sweep rate, electrode radius, charge transfer coefficient and rate of charge transfer are studied. Disc and pipette electrochemical responses are compared over a range of experimental parameters. The simulation method presented is fast, accurate and stable over a wide range of experimental parameters and is easily adapted to different electrode geometries and experimental techniques.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:662758 |
| Date | January 1991 |
| Creators | Taylor, Gordon |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/13078 |
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