Positron annihilation studies of poly(pyrrole) films

Positron annihilation measurements are reported over a temperature range from 300 to 370 K on films of poly(pyrrole) produced by electrochemical polymerization of pyrrole in a solution of acetonitrile with silver p-toluenesulphonate as electrolyte. The synthesis was carried out in anhydrous conditions. The positron annihilation lifetime data were resolved into two components. The intensities and lifetimes were found to be weakly dependent on temperature. The data resemble more closely the behaviour observed in metals rather than in a polymeric material. The spectrum is believed to reflect annihilation of delocalized and localized positrons: the intensities of the two components reflect the properties of positronium trapped in defects. These observations are consistent with a high electron mobility in these polymeric materials. (author)