Influence of solvent and acid on electrical properties of synthesized polypyrrole films

The conducting polypyrrole films are synthesized. They are coated on the surface of the tantalum electrode by electrochemical deposition in air. It is found that mechanical abrasion facilitates the increase of defect sites and promotes the formation of polypyrrole films. The aging mechanism of the supporting electrolyte solution is analyzed for determining the effect of solvent components on the electrical properties of the polymer films. Because the protonation of pyrrole monomer is the crucial factor of the supporting electrolyte solution aging, the mixture of 1,2-propanediol carbonate (PC) with stronger nucleophilicity and acetonitrile (AN) with weaker nucleophilicity is used as the solvent. Finally, the influence of hot-acid treatment on the properties of synthesized polypyrrole films is discussed. It is shown experimentally that the organic and inorganic acid treatments tend to enhance the conductivity.