A study of the fractal dimensions of the electrodeposited poly-ortho-aminophenol films in presence of different anions

Fractal dimensions of the electrodeposited poly-ortho-aminophenol (POAP) films formed in the presence of Cl−, SO42−, NO3− and ClO4− anions are investigated by the methods of electrochemical impedance spectroscopy and cyclic voltammetry. In the former, the extent of the “squashedness” of the semi-circle in the Nyquist plots and in the latter the slope of maxima of the diffusion current vs. the potential sweep rates in the logarithmic scale are used. The fractal dimensions in the 2.33–2.46 range are obtained and good agreement exists between the findings of the two methods. The length scale, the distances between two nearest points that the anions somehow sense (by a yardstick of the size of their jump-lengths), were also derived and were found to be in the 1.4–11.7 Å range.