Synthesis of polyaniline films by plasma polymerization

This work presents a study on the formation of polyaniline films by plasma polymerization using RF glow discharges with resistive coupling between stainless-steel electrodes. The polymer was obtained at a frequency of 13.5 MHz and pressure in the range (2-8) × 10^-2 Torr. Polyaniline and I₂-doped polyaniline films were synthesized as thin films that can be adhered to glass and metal surfaces. The IR analysis shows the characteristic polyaniline peaks with evidence that some benzene rings are broken by the discharge energy. The thermogravimetric analysis shows an increase in polymer decomposition as a function of the time of synthesis. This effect, the physical characteristics and solubility of the film suggest crosslinking in the polymers due to the continuous impact of the electronic rain. The way in which the relative humidity affects the electric conductivity of plasma polyaniline films was established. At room temperature and relative humidity of 40% the conductivity was between 10^-10 and 10^-12 S/cm. When the films were synthesized with I₂, the electric conductivity ranged from 10^-4 to 10^-11 S/cm with relative humidity from 40 to 90%.