Combined EQCM and probe beam deflection study of salicylate ion transfer at a polypyrrole modified electrode

Abstract

The transfer of salicylate ion at a polypyrrole-modified electrode during redox switching has been studied by a combined electrochemical quartz crystal microbalance (EQCM) and probe beam deflection (PBD) technique. The gravimetric and optical responses indicate an exchange process involving a successive two-stage ion exchange process in which sodium ion transfer in one direction precedes salicylate ion transfer in the opposite direction. During film reduction, sodium ions enter the polymer prior to salicylate ion release. A comparison of the predicted PBD profile, with that of the measured beam deflection response, calculated by temporal convolution of the current signal, indicates that neutral species, including salt, accompany anion release during film reduction.