Dielectric and conductivity studies of cyclodextrins

Dielectric and conductivity studies of α- and β-cyclodextrins, their derivatives and inclusion complexes with various guest molecules, have been performed by AC spectroscopic techniques in the frequency range 10 Hz-1 GHz and the temperature range -11 to 23°C. A dispersion appearing in all cases is displaced towards the lower frequencies with decreasing temperature and its overall behaviour depends markedly on the CD type, the degree of substitution, the nature of the guest molecule and the water content of the CD sample. The activation energy and the pre-exponential factor of the relaxation mechanism have been evaluated in the various cases and the results are discussed in comparison with data obtained with the same or identical samples by the same authors with the TSDC technique (ISE7) and with data reported in the literature