Abstract
Ultrasonic fields were applied to the electropolymerization of pyrrole as a novel technique to control the properties of the conducting polymer. The p-toluenesulfonate-doped polypyrrole films prepared in the ultrasonic fields exhibited a more negative cathodic peak than those prepared in the silent conditions in the cyclic voltammograms. This voltammetric change at the reduction process was explained as change from the anion undoping to the cation doping, and attributed to formation of a highly dense film. Hence, a polypyrrole ClO_4^- -selective electrode has been prepared successfully by polymerizing pyrrole in ClO_4^- solution on a platinum-wire with and without ultrasonication. Both electrodes give Nernstian potentiometric responses in the range of the 10^<-1> - 10^<-4> M ClO_4^-. In the presence of various interfering ions, the selectivity for ClO_4^- of the electrode prepared under ultrasonication is higher than that prepared without ultrasonication. Thus, the polypyrrole films prepared under ultrasonication exhibit unique electrochemical properties in a doping/undoping process and excellent properties as the ClO_4^- -selective electrode.
