Electroactive Multilayer Films of Polyaniline and Vanadium Pentoxide

Abstract

Nanoscale composites of polyaniline (PANI) and vanadium oxide (V2O5) were assembled via the electrostatic layer-by-layer (LBL) technique, with a thickness per bilayer of 2.5 nm. Interactions between PANI and V2O5 are maximized in comparison to the usual xerogel films due to the nanostructured nature of the LBL films, in which V2O5 causes PANI to be oxidized. This has been demonstrated in Raman spectroscopy measurements and is consistent with electrochemical data. These strong interactions make the LBL film to display a color that is different from the colors of the individual materials. Furthermore, they promote a cooperative effect that enhances the charge storage capability of the films, with a total charge of 2.25 mC cm-2 for the PANI/V2O5 LBL films, in comparison with 1.86 mC cm-2 for the sum of the isolated contributions from PANI and V2O5.