Surface potentials of polyaniline LB films

The surface potential (V-LB) Of Langmuir-Blodgett (LB) films of pure emeraldine base polyaniline (PANi) and mixtures of PANi and cadmium stearate (CdSt) was investigated. Protonated PANi LB films produced from acidic subphases displayed higher VLB than the nonprotonated films transferred from monolayers spread on pure water. For the mixed LB films, VLB increased with the amount of PANi, and it was always positive regardless of whether an odd or even number of layers were deposited, in contrast to the switch-over from positive to negative potential when going from an odd to an even number of layers for pure cadmium stearate LB films. The results have been analyzed by taking account of the negative contribution from the substrate/film interface.