Chemical syntheses of the conducting material formed by heteropolyacids and polyaniline

Here we report a hybrid organic-inorganic conducting material formed by vanadium-containing silicotungstic/molybdic or phosphotungstic/molybdic acid and polyaniline (PAN) with a one-step or a two-step chemical reaction involving oxidation of aniline with ammonium persulfate in the presence of vanadium-containing silicotungstic/ molybdic or phosphotungstic/molybdic acid. Polymer structure was examined by elemental analysis, IR, XRD, XPS, and thermal stability and conducting behavior was studied. Results showed that the composition and structure of main chain with one-step method were similar to that with two-step method. However, some differences in XRD spectra between the polymer with one-step and two-step methods were observed, which may be due to differences of doping methods. Conductivity of materials with a one-step method was bigger than that with a two-step method when the percentage of doping was determined. When heteropolyacid as doping agent was determinate, conductivity increased with doping percentage at the beginning and rate of conductivity was faster in the two-step method than in the one-step method. However conductivity did not increase with doping percentage when the doping percentage increased to a certain range. The conductivity of the materials descended after the materials were heated. One reason was dedoping or degradation of the materials.