Electropolymerization and conductivity of inhibitors with 2–(5–aminopentyl) benzimidazole

Polymer layers of inhibitors are supposed to be electronically and ionically insulating. Potentiostatic investigations of film growth with PAB demonstrated a self-inhibiting process which is explained by the limiting electron conductivity of the polymer. Correspondingly, the electrode capacity C decreases with film thickness d, but the potential drop extends over a thin inner film only with an effective thickness d_eff << d. These results are consistent with the decrease of the current density i of electron transfer reactions. The long-time behaviour of the films is more complex since ions can slowly diffuse into the film. Small ions, like protons, and molecules, like water, can rapidly move through the film. Hence, oxide formation can take place at the metal/PPAB interface. Conductivity data are estimated.