1998 Volume 14 Issue 3 Pages 535-540
We have fabricated composite films of polypyrrole/quinone sulfonate via electropolymerization. The FTIR investigation indicated the incorporation of quinone sulfonate in the polypyrrole (PPy) film to compensate for a positive charge in the polymer chain. Further, the elemental analysis of PPy/9,10-anthraquinone-2-sulfonate (AQS-) showed that 0.29 of the sulfonate was incorporated per pyrrole unit. Cyclic voltammetric results in dimethylsulfoxide and dimethylformamide solutions showed that the two 1-electron transfer steps could be assigned to the formation of radical dianion (AQS2-.) and trianion (AQS3-). The positive shift of the first cathodic peak for the incorporated AQS- indicated a strong interaction between the dianion and the cationic sites of the polymer. The PPy/AQS- film worked as a cation-exchanger at electrode potentials below about -0.3 V vs. Ag/AgCl (saturated KCl) because of the creation of the anionic sites of the reduced quinone.