Interaction between electroconducting polymers and C-60

The combination of outstanding properties of fullerenes as good electron accepters and conducting polymers as excellent donors was taken into consideration. For investigation, polyaniline was chosen due to the nucleophilic character of the NH groups. The possibility of charge transfer interaction between C-60 and emeraldine base of polyaniline during the formation of solution casting films was carefully studied. Physico-chemical properties of the formed films were investigated using microscopic analysis (SEM, AFM), EPR investigation and conductivity experiments. A small increase of one order in their electrical conductivity was found. Semiconducting behaviour of the formed films was confirmed through the temperature dependence. All the investigations dearly proved a strong effect of solvent, i.e. N-methylpyrrolidinone (NMP) on the characteristics of the doped films. Kinetics of the mutual interaction between the C-60 solution and NMP was also studied by spectral analysis. The nucleophilic addition of NMP on C-60 is suggested rather than a complete charge transfer. The small increase in electrical conductivity and almost unchanged EPR characteristics are indicative of hardly noticeable charge transfer due to the steric hindrance caused by the large size of fullerene molecules.