Preparation and Characterization of a New Conducting Polymer from O-aminoazotoluene Azo Dye

✍ Scribed by Hyman H. Rehan

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 154 KB
• Volume: 32
• Category: Article
• ISSN: 0933-5137
• DOI: 10.1002/1521-4052(200103)32:3<266::aid-mawe266>3.0.co;2-s

✦ Synopsis

Anodic polymerization of o-aminoazotoluene azo dye on platinum electrodes in 0.5 M HCl in 50% v/v ethanol/water and in MeCN was studied by cyclic voltammetry. The formed films, in both media, were electroactive in acidic solutions but electroinactive in neutral and alkaline solutions and aprotic MeCN. The pair of redox peaks due to the electroactivity is attributed to a 1:1 proton electron elimination (on oxidation)/addition (on reduction) at the amino/imino linkages which connect the aromatic nuclei. Chronocoulometry showed that the kinetics of these processes were dominated by the transport of solvated protons and Cl À ions through the polymer films. Reduction of the polymer films in acid solutions led to their gradual degradation due to the irreversible reduction of the azo groups in the polymer skeleton, while the reversible reduction of these groups in MeCN saved the polymer from degradation. The rate of electron transfer reactions of the redox couple [Fe(CN) 6 ] 3À/4À on polymer-covered platinum electrodes decreased substantially with increasing the polymer film thickness.