Characterization of highly conducting lithium salt doped polyaniline filmsprepared from polymer solution

We have developed a new method for preparing conducting polyaniline (Pani) films and investigated their chemical and physical properties by means of U V-Vis, FT-IR, EPR, XPS, and do conductivity measurements. Conducting polyan iline films are prepared by casting from the solution of polyaniline with l ithium salt. The free-standing films have relatively high do conductivity w ithout further treatment with HCl. The effects of lithium salts, such as Li BF4, LiPF6, and LiClO4, and their concentrations on do conductivity are stu died. The do conductivity of Pani-LiBF4 film has been found to be better th an those of Pani-LiPF6 and Pani-LiClO4 films. The do conductivity of the sy stems increases with increasing lithium salt concentration in the range fro m 0.025 to 0.1 M, and exhibits a maximum value of similar to 10(-1) S/cm. w hen 0.1 M LiBF4 is doped. (C) 2001 Published by Elsevier Science Ltd.