Cyclic voltammetry redox capacity

Cyclic voltammetry for a quick determination of the domain of electroactivity, the number of active redox couples (phases), the electrochemical reversibility, and, to some extent, the capacity and the cyclability. 

In general, the determination of the redox processes and the evaluation of antioxidant capacity can be achieved by electrochemical techniques, such as cyclic voltammetry. On the other hand, as free radicals are very reactive they are usually analyzed by measurements of secondary products (H2O2, oxidized proteins, etc.) by fluorimetry in combination with fluorescent dyes, such as dichlorofluorescein. This procedure offers more advantages than the classical spectrophotometric determination based on the oxidation of o-dianisidine, due to which the sensitivity of this last procedure is limited to 200nmoll H2O2 under ideal conditions. 

As charge is inserted or removed at low rates, the polymer film behaves as a (redox) capacitor. The redox capacity of electroactive films is a quantity of fundamental importance, and it may be determined by several complementary techniques including cyclic voltammetry, electrochemical impedance and coulometric titration. Cyclic voltammetry of a redox polymer film at a slow... 

The electrochemistry of conducting polymer films discussed above has emphasized the macroscopic, near-equilibrium processes which occur when the redox reactions are studied at low rates. The electroactive film has been taken to be thin, and diffusion processes are rapid enough to maintain a uniform concentration throughout the film as the oxidation state is varied from completely reduced to completely oxidized. Cyclic voltammetry has been widely used to characterize the behaviour, the stoichiometry and the redox capacity of electroactive films in this limit. 

Hunter et al [102] used both impedance and cyclic voltammetry to measure Cl for poly(vinylferrocene) films. Good agreement was found for Cl determined by the two independent techniques. Ho et al [103] had shown earlier that impedance techniques could be used to study insertion processes for intercalation oxides, but were unable to make observations at low enough frequencies to observe the redox capacity region. Mermillod et al [61] determined Cl with impedance and cyclic voltammetry on electrodes fabricated from poly(pyrrole) powders. 

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