Polyaniline cyclic voltammetry

Electrochemical deposition of poly(l,2-diaminobenzene) and polyaniline, cyclic voltammetry and amperometry were performed using a Sycopel Scientific AEW2 portable electrochemical workstation... 

Polyaniline (PANI) was investigated as electrocatalyst for the oxygen reduction reaction in the acidic and neutral solutions. Galvanostatic discharge tests and cyclic voltammetry of catalytic electrodes based on polyaniline in oxygen-saturated electrolytes indicate that polyaniline catalyzes two-electron reduction of molecular oxygen to H2O2 and HO2". 

Apart from the insulating polymeric matrices, conductive polymers such as polypyrrole and polyaniline have been used as nanocomposite electrodes by chemical or electrochemical polymerization [13, 17, 116, 117]. Such materials provide high conductivity and stability. However, the use of insulating polymers can be more advantageous than the conductive polymers when employed in cyclic voltammetry. 

T. Trung, T. H. Trung, and C.-S. Ha, Preparation and cyclic voltammetry studies on nickel-nanoclusters containing polyaniline composites having layer-by-layer structures, Electrochim. Acta, 51, 984—990 (2005). 

Figure 17.3 ESR spectra of nanostructured polyaniline samples (each of 10 mg) prepared at different potential scan rates (1) 6, (2) 12, and (3) 60 mV s (Reprinted with permission from Journal of Physical Chemistry B, Spectral Characteristics of Polyaniline Nanostructures Synthesized by Using Cyclic Voltammetry at Different Scan Rates by Shaolin Mu et al., 112, 37, 11558-11563. Copyright (2008) American Chemical Society)...

Electrochemical oxidation and reduction of polyanilines has been extensively studiedlO,23,24 by cyclic voltammetry techniques, usually in aqueous acid solutiorv using either electrochemically synthesized polyaniline films/ or chemically synthesized powders. This is a convenient method for the electrochemical doping of extremely small amounts of leu-coemeraldine but it is not well suited for the synthesis of large quantities of oxidatively doped polymer in a known oxidation state. 

FIGURE 18.10 Cyclic voltammetry (CV) of thin films of highly sulfonated polyaniline deposited from solution (HSPAN) and similar material synthesized by reduction of emeraldine salt by sulphite ion followed by oxidation (ES + HS03 - - O2). (Reprinted from Barbero, C., H.l. Salavagjone, D.E Acevedo, D.E. Grumelli, F. Garay, G.A. Planes, G.M. Morales, and M.C. Miras. Electrochim. Acta., 49, 3671—3686, 2004. With permission.)... 

Several ring-substituted anilines (o-toluidine, m-toluidine, o-anisidine, and o-chloroaniline) were electrodeposited on passivated Fe surfaces by cyclic voltammetry, potentiostatic, or galvanostatic techniques from aqueous oxalic acid solutions [180]. With the exception of o-chloroaniline, the films exhibited protective properties against corrosion of Fe in sulfuric acid solution by stabilizing the Fe passive state, though performance was slightly poorer than that of polyaniline. 

G. Pistoia, G. Montesperelli, P. Nunziante, Polyaniline derivatives - an investigation by cyclic voltammetry and impedance spectroscopy, Journal of Molecular Electronics 1990, 6, 89. 

Cyclic voltammetry of polyaniline obtained in the presence of the three polyelectrolytes was very similar and presented two redox pairs. The absence of the third intermediate redox pair is evidence of linear chain formation. The scanning electron micrographs indicate a fibrillar morphology for polyanilines obtained with perchloric and p-toluene sulfonic acids and globular for those blended with the other polyelectrolytes. 

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