DigiSim program

Figure 6,16 Cyclic voltammograms as a function of scan rate. This figure comprises traces simulated by the DigiSim program for a reversible one-electron couple, with the fastest scan rate being shown outermost. Reprinted with permission from Current Separations, Vol. 15, pp. 25-30, copyright Bioanalytical Systems, Inc., 1996.

The DigiSim program probably represents the current state of the art which is achievable for simulating and analysing cyclic voltammograms. This package can perform cyclic voltanunetry for a wide range of mechanisms at planar, spherical, cylindrical or rotated disc electrodes. It also computes concentration profiles. 

The DigiSim program enables the user to simulate cyclic voltanunetric responses for most of the common electrode geometries (planar, full and hemispherical, and full and hemicylindrical) and modes of diffusion (semiinfinite, finite and hydrodynamic diffusion), with or without inclusion of IR drop and double-layer charging. 

I also wish to thank Dr Lou Coury and Dr Adrian Bott of Bioanalytical Systems, Inc. for their enthusiasm, and permission to reproduce Figures 6.16, 6.18, 6.19, 10.1 and 10.3.1 gladly thank Dr Manfred Rudolph for his description of the DigiSim program. Dr Mike Dawson of E G G for his help concerning the Condecon program, and Dr Keith Dawes of Windsor Scientific for his help, and the permission to reproduce Figure 10.2. 

Salimi nsed the DigiSim program to analyze the electrochemical properties of an aqueous dye, thionin, at a range of pH valnes. When thionin is electrochemically rednced it can act as a catalyst for Cr(VI) reduction. DigiSim... 

The programs described above are limited in scope, and a superior approach is to employ a simulation package. There are three commercial programs at the forefront of the market, namely DigiSim, Condecon and GPES. 

While several sample programs are available, nowadays a preferred and simpler process is to simulate the system via the use of more sophisticated packages such as DigiSim, Condecon or GPES. 

The Feldberg approach to digital simulation [229] uses a somewhat different method of discretisation, and the method is alive and well it is, for example, the basis for the commercial program DigiSim [482], It begins with Fick s first diffusion equation, using fluxes between boxes or finite volumes, rather than concentrations at points in the discretisation process (see below). 

One of the authors of DigiSim has now produced his own separate program, DigiElch, available through a web site [14]. Presumably it functions much like DigiSim. 

Another key computational advance in electrochemistry has been the development of convenient programs for simulating voltanunetric responses. Such programs, which can be run on conventional personal computers, allow for determination of fundamental electrochemical parameters and reaction rates for coupled chemical reactions. Because of the prevalence of cyclic voltammetry, the majority of such applications are performed using DigiSim, which calculates... 

Rudolph, M. Reddy, D. P. Feldberg, S. W. Anal. Chem. 1994,66,589A. DigiSim 1.0 program Bioanalytical Systems Inc., West Lafayette, Indiana (http //www.bioanalytical.com 800. 

One of the authors of DigiSim has produced his own separate program, DigiElch [67] which is now distributed by Gamry Instruments [68]. Besides one-dimensional diffusion DigiElch is also capable of two-dimensional diffusion simulations for UMBEs and UMDEs. CV, chronoamperometry, square wave voltammetry and electrochemical impedance spectroscopy can be simulated. 

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