Characterization of highly conducting lithium salt doped polyaniline films prepared from polymer solution

Abstract

We have developed a new method for preparing conducting polyaniline (Pani) films and investigated their chemical and physical properties by means of UV–Vis, FT-IR, EPR, XPS, and dc conductivity measurements. Conducting polyaniline films are prepared by casting from the solution of polyaniline with lithium salt. The free-standing films have relatively high dc conductivity without further treatment with HCl. The effects of lithium salts, such as LiBF 4, LiPF 6, and LiClO 4, and their concentrations on dc conductivity are studied. The dc conductivity of Pani–LiBF 4 film has been found to be better than those of Pani–LiPF 6 and Pani–LiClO 4 films. The dc conductivity of the systems increases with increasing lithium salt concentration in the range from 0.025 to 0.1 M, and exhibits a maximum value of ∼10 −1 S/cm when 0.1 M LiBF 4 is doped.