Influence of Solvent and Acid on Electrical Properties of Synthesized Polypyrrole Films
Xu Youlong, Ji Rui,Wang Fei
(Xi'an Jiaotong University,Xi'an 710049,China)

Abstract: The conducting polypyrrole films are synthesized. They are coated on the surface of the tantalum electrode by electr ochemical deposition in air. It was found that mechanically abrading facilitates the increase of defect sites and contributes to the formation of polypyrrole films. The aging mechanism of the supportingelectrolyte 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 aging of the supporting electrolyte solution, the mixture of 1,2-propanediol carbonate (PC) with stronger nucleophilicity and acetonitrile (AN) with weaker nucleophilicity was 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 treatmentstend to enhance the conductivity.
Keywords: polypyrrole;electrodepos ition;conductivity;nucleophilicity;acid treatment