AC impedance analysis of non-faradaic process of poly (N-dodecylacrylamide) Langmuir-Blodgett films on electrodes

The membrane resistance (R-M) and membrane capacitance (C-M) of two kinds of polymer LB films, N-dodecylacrylamide (DDA) homopolymer and DDA copolymer with ionic ruthenium complex (R-u), on HOPG electrodes were investigated as a function of number of layers (n) using AC impedance spectroscopy. The equivalent circuit models of these polymer LB films were proposed from the complex impedance and capacitance data. The pDDA LB films showed a good dielectric behavior with high R-M around sub M Omega cm(2). Meanwhile, the resistance of the R-u copolymer LB films showed about one order of magnitude smaller than that of the DDA LB films because ionic ruthenium sites behaved as ion channels.