Heavy ion irradiation on conducting polypyrrole and ZrO2-polypyrrole nanocomposites

Heavy ion irradiation on conducting polypyrrole (PPy) and ZrO2-polypyrrole (ZrO2-PPy) nanocomposites were carried out with an aim to illustrate the suitability of these materials for use in various space probes where they might be exposed to different cosmic radiations. Polypyrrole and ZrO2-polypyrrole nanocomposite samples were prepared from aqueous solution of pyrrole and pyrrole suspended in colloidal dispersion of ZrO2, respectively, by adding FeCl3 solution as the oxidant. The precipitates were washed, dried and pressed into pellets for conductivity measurement. Conductivity and other physical properties were measured before and after irradiation in both the cases. Pure polypyrrole and nanocomposite samples were irradiated with 50 MeV 16 0 beam for 5 h. After irradiation it was found that in case of ZrO2-PPy nanocomposite samples, electrical conductivity decreased to very small extent while in case of pure PPy samples conductivity decreased drastically (from 4.7 to 2 x 10(-5) S/cm) with O-16 beam. Samples were further characterized by thermogravimetry (TGA) and X-ray diffraction (XRD) before and after irradiation. Results indicate that electrical conductivity of the nanocomposites are very little affected by irradiation with heavy ions but the conductivity of the pure polypyrrole is much more susceptible to heavy ion irradiation. (C) 2004 Elsevier B.V. All rights reserved.