Thermal Properties of Conducting Polypyrrole Nanotubes |
| A. Rudajevováa, M. Varga b, J. Prokeš b, J. Kopecká c and J. Stejskal d
aCharles University in Prague, Faculty of Mathematics and Physics, Department of Condensed Matter Physics, 121 16 Prague 2, Czech Republic bCharles University in Prague, Faculty of Mathematics and Physics, Department of Macromolecular Physics, 180 00 Prague 8, Czech Republic cFaculty of Chemical Engineering, Institute of Chemical Technology Prague, 166 28 Prague 6, Czech Republic dInstitute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, 162 06 Prague 6, Czech Republic |
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| Thermal properties of polypyrrole nanotubes synthesized by the chemical oxidation of pyrrole with iron(III) chloride in the presence of methyl orange as structure-guiding template, have been investigated. As-prepared polypyrrole salt and corresponding base were compressed into pellets. Thermogravimetric analysis has shown that the heating/cooling of both polymers is connected with water desorption/re-absorption. This process influences all temperature dependences of the thermophysical properties. The specific heat of both polypyrrole forms was the same at 35°C. The thermal diffusivity of polypyrrole base was lower than that of the salt. The dilatational characteristics are strongly influenced by water desorption/re-absorption. Water desorption is connected with the contraction of polypyrrole and its re-absorption with the expansion of polypyrrole. The electrical resistivity was measured, in analogy to thermal experiments, by a four-point van der Pauw method. The electrical resistivity was 0.016 and 10.2 Ωcm at room temperature, for both materials. The electrical resistivity was also influenced by water desorption/re-absorption as well as other thermophysical properties. |
DOI: 10.12693/APhysPolA.128.730 PACS numbers: 72.80.Le, 66.70.Hk, 65.40.De, 66.30.Xj |