National Repository of Grey Literature 2 records found  Search took 0.01 seconds. 
Voltage-step Transient in Redox Systems II. 1D Approximation (revisited)
Wein, Ondřej
Using the well-known Cottrell asymptote, voltage-step transient experiment could provide data on bulk concentration and diffusion coefficient of working depolarizer, essential in the liming-current techniques. However, the Cottrell asymptote is not directly applicable in an early stage of the voltage-step transient process,. There are three additional transport resistances that cannot be neglected at extremely high initial currents: Faradaic resistance at surface of working electrode, Ohmic losses in its intimate neighborhood, and the galvanometric constraint in the outer circuit (galvanometer, current follower, potentiostat). Non-linear effect of these additional transport resistances on the transient current is calculated in a 1D approximation, i.e. assuming uniform accessibility of the working electrode, for finite voltage steps.
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Edge Effects in Voltage-step Transient I. Ohmic Losses in 1D Approximation (revisited)
Wein, Ondřej
Ohmic potential drop between the working and reference electrodes plays an important role in the early stage of the voltage-step transient process. Non-linear effect of the ohmic drop on the transient currents has been calculated for large voltage steps, assuming reversible behavior (negligible surface overpotential) of a redox couple O + ne = R. This report extends an older study by Wein (1991). In particular, it adds a series of analytic approximations and gives more accurate numerical solving.

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