Theoretical and experimental studies of conducting polymer polyaniline / electrolyte interface by impedance spectroscopy

Abstract A fractal model is proposed to explain the origin of “constant phase angle” (CPA) elements often observed in interfacial impedance between blocking electrode and electrolyte. Universal relation between CPA exponent η and surface fractal dimension D s , η = 3 − D s , has been obtained. Based on our theoretical results, impedance spectroscopy can be used as a new experimental approach for surface (interface) study, especially for conducting polymers. Some interesting information about structure and electrochemical polymerization process of polyaniline have been obtained from impedance spectra of polyaniline / electrolyte interface.