Polypyrrole-based electrode coatings switchable electrochemically between the anion- and cation-exchanger states

✍ Scribed by Chuanjian Zhong; Karl Doblhofer

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 607 KB
• Volume: 35
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(90)87107-d

✦ Synopsis

Dodecylsulphate was incorporated into a polypyrrole matrix during anodic polymerization of pyrrole. The concentration was adjusted such that in the oxidized film about one half of the polypyrrole cationic groups was charge compensated by the sulphate groups from the incorporated dodecylsulphate, the second half by anions from the electrolyte. Upon electrochemical oxidation/reduction, the film is reversibly "switched" between a cation-exchanger (at negative electrode potentials), and an anion exchanger (at more positive potentials) state. The different states of the film are characterized by electrochemical, EDAX, and in particular by Volta-potential measurements. The Donnan potentials determined with the latter technique as a function of electrode potential and electrolyte concentration were in good agreement with calculated values.