The In Situ ESR and Electrochemical Behavior of Poly(aniline) Electrode Films

Abstract

Poly(aniline), when immersed in acid electrolytes, is an electronic conductor between 0.2 and 0.8 V_sce. Concurrent measurements of ESR absorption and injected charge during a potential scan across this region reveal a major increase in paramagnetism within the conducting regime, with sharp maxima near 0.2 and 0.8V. A 1:1 ratio of spins to electronic charges is found at the 0.2V transition. Lineshape analysis indicates rapid, three‐dimensional spin diffusion due to spin exchange. Electron delocalization is invoked to explain the correspondence of the potential dependence of the ESR absorption with a one‐dimensional density‐of‐states function.