Influence of electrode pretreatment, counter anions and additives on the electropolymerization of pyrrole in aqueous solutions

Polypyrrole behaves as essentially different materials when prepared under slightly different conditions. In this work the effect of pretreatment of the working electrode with 4-aminothiophenol, decanethiol, allyl alcohol and cysteamine is studied. The pretreatment enhances in some cases the early stages of polymerization, but the beneficial effects are small. Polymers synthesized in the presence of surfactants or organic dopants are superior to those polymerized in the presence of small inorganic anions. Additives such as 3- and 4-nitrophenol have minor effects on the polymerization of pyrrole, but 2,4,6-trinitrophenol improves significantly the quality of the polymers.