Electrochromic and conductivity properties: a comparative study between melanin-like/V2O5 center dot nH(2)O and polyaniline/V2O5 center dot nH(2)O hybrid materials

In this work, we report the synthesis and some properties of melanin-like/2 VO5 . nH(2)O and polyaniline/V2O5 . nH(2)O hybrid materials that have poten tial applications in optics and electronics. The hybrid materials were obta ined by an oxidative polymerization/intercalation process reacting the gel with the monomers of the polymers. The optical properties of the compounds in film forms were measured using ultraviolet-visible (UV-Vis) spectroscopy . Thermogravimetric analysis, differential gravimetric analysis and de cond uctivity techniques were also used to study the compounds. The X-ray diffra ctograms indicate that the lamellar structure of the V2O5 is preserved with the increase of the inter-planar space from 1.18 +/- 0.05 to 1.40 +/- 0.05 nm. The presence of the organic phase induced the reduction of V(V) ions t o V(IV) and increased the de conductivity and affected the spectroelectroch emical properties of the samples. (C) 2000 Elsevier Science B.V. All rights reserved.