Water and ammonia influence on the conduction mechanisms in polyacrylic acid films

Polyacrylic acid (PAA) and ammonium polyacrylate (NH4PA) films realised on quartz substrate with platinum interdigitated electrodes have been investigated under controlled atmosphere by the means of impedance spectroscopy and square-wave potentiostatic experiments. Using the standard analysis of Cole–Cole plots, the dependence on ambient conditions of the equivalent circuit parameters has been derived. The samples’ behaviour indicates two different conduction mechanisms, which depend on the humidity and ammonia content of the ambient. Additionally, infrared transmission spectroscopy measurements were performed on PAA films deposited onto Germanium optical windows in order to study the irreversible reaction of PAA with ammonia in humid air.