Properties of polyaniline formed at tin dioxide electrodes in weak acid solution: effect of the counterion

Conducting polymers from aminobenzoic acids and aminobenzenesulphonic acids: influence of pH on electrochemical behaviour

“…Nevertheless, on placing these films in acid solution, protons enter the film and they exhibit the normal electrochemical characteristics of polyaniline, despite the physical differences in the film. This reversible behaviour with respect to counterion and proton insertion has been observed on switching between sulphuric acid and acetate buffer solution in the presence of different counterions [35].…”

“…The substituent certainly reduces the influence of the pH value. The position of the peak potential is influenced by pH, and also by the counterion [35]. Between pH 0 and 1 this effect led, in general, to a shift in the first oxidation peak to a higher potential, while the second peak was shifted to a lower potential.…”

“…However, the films are more compact at higher pH owing to the lower growth rate and scanning electron microscopy demonstrates that the fibrous open nature of films formed in strong acid solution is lost [35]. Nevertheless, on placing these films in acid solution, protons enter the film and they exhibit the normal electrochemical characteristics of polyaniline, despite the physical differences in the film.…”

Electropolymerisation and properties of conducting polymers derived from aminobenzenesulphonic acids and from mixtures with aniline

“…This modi®cation of the polymer structure is referred to as``self-doping'' in order to distinguish it from`e xternal doping'', which is due to the introduction of different counter-ions which can also in¯uence the properties of the ®lm, e.g. [2,3]. Acidic groups which can be used as aniline ring substituents are phosphonic [4], carboxylic [1,5,6] and sulphonic [5,7±11].…”

Voltammetric and in situ FT-IRS study of the electropolymerization of o-aminobenzoic acid at gold and graphite carbon electrodes: Influence of pH on the electrochemical behaviour of polymer films

“…53 A major limitation to the industrial exploitation of PANI derives 54 from the fact that, on increasing the pH either during electrosyn-55 thesis or during operation, a significant drop of the electrical 56 conductivity takes place. It was thought that the problem could 57 be solved by the selection of specific counterions [15][16][17][18][19]. The role as an interesting option to achieve this purpose [20][21][22].…”