Measurement of lateral charge propagation in polyaniline layers with the scanning electrochemical microscope

The local injection and lateral propagation of charge in ultrathin polyaniline (PAN) layers have been studied with the scanning electrochemical microscope (SECM). Monolayers of PAN were deposited on a glass substrate using the LB method and were chemically reduced using sodium dithionite. A microelectrode held close to the PAN layer was used to generate a flux of an oxidant, i.e., Fe(phen)(3)(3+) (phen = 1,10-phenanthroline) which diffused to the surface and locally oxidized the reduced PAN. By simulating the current-time transients, the kinetics of lateral charge propagation have been evaluated.