Abstract

Flexible, conducting polyaniline/V₂O₅ nanocomposite films (PAPSA)_xV₂O₅ were prepared by simply mixing water soluble polyaniline, poly(aniline-co-N-(4-sulfophenyl)aniline) (PAPSA), with V₂O₅ at room temperature. Two types of (PAPSA)_xV₂O₅ films with different solubility were isolated. XRD data showed that the interlayer spacing of the water-soluble (PAPSA)_xV₂O₅ film, in which the polymer chains occupied the vacancies of V₂O₅ xerogel, is ca. 11.5 ± 0.5 Å. The d-spacing of the water insoluble (PAPSA)_xV₂O₅ film (small amount, <5%) is 13.5 ± 0.5 Å, which is consistent with the insertion of polyaniline chains into the V₂O₅ interlayer space. In both phases, PAPSA and V₂O₅ were homogeneously mixed as revealed with SEM, depth profile SIMS and Auger analyses. The room-temperature conductivity of the water-soluble (PAPSA)_xV₂O₅ film was in between those of a PAPSA pellet and a V₂O₅ xerogel and the conductivity increased with temperature, characteristic of thermally activated behavior. Cyclic voltammograms of the nanocomposite films showed two pairs of red-ox peaks with good reversibility. The color of the films can be yellowish green, green, brown, orange or purple, depending on the applied potential and the stoichiometry of the composites. (PAPSA)_xV₂O₅ has much better electrochemical stability relative to PAPSA and its mechanical properties are superior to that of V₂O₅ xerogel.