STUDY OF THE ACTION OF GASES ON A POLYPYRROLE FILM

D.c. conductivity measurements are performed on PPy films initially doped with Fe(CN)64-, then exposed to diluted O2, NH3, NO2 in N2 or air. By working at 100 °C and after a stabilizing treatment, some NH3 sensor ability is found for high concentrations, but this requires the measurement of very low currents. The doping kinetics are analysed as both Elovich superficial adsorption and diffusion in the bulk. A poisoning effect of NO2 is observed, and afterwards the possibility of 'n' doping as by NH3 is demonstrated. © 1990.