Molecular mobility in polyaniline studied by ESR method

For emeraldine salts of polyaniline (ES), segmental motions in precipitated ES and large-scale rearrangements of ES globules in solutions of polyaniline in N-methylpyrrolidinone (NMP) were found, in spite of the formation of salt bridges between polyaniline chains. For precipitated ES it was found that the asymmetry of the Dysonian ESR line correlates with macroviscosity of solvent. This observation reveals the important role of segmental motions of polyaniline chains in conductivity of ES at microwave frequency. For solutions of ES in NMP the broadening of the ESR lines at room temperature and 77 K was found at dilution of the solutions. This observation shows the increase of the distances between paramagnetic centres of ES with the dilution.