The determination of the activation energy of a relaxational process from thermally stimulated depolarisation currents (TSDC) data: an illustration with the β-relaxation of maltitol

Three different and independent procedures to obtain the activation energy of a motional process from thermally stimulated depolarisation currents (TSDC) data are reported. One of the procedures requires a single thermal sampling (TS) experiment: the activation energy is calculated from the temperature dependence of the relaxation time associated with this TS peak. The other two procedures are based on the influence of the heating rate on the features of the TS peak namely, on the temperature location Tm and on the intensity of the maximum I(Tm) of the peak. The illustration with the case of an elementary component of the β-relaxation of maltitol shows that the values of the activation energy provided by these procedures are in good mutual agreement. The fact that the TSDC technique provides different and independent procedures to obtain the kinetic parameters of a motional process is a unique feature in the context of the experimental techniques most often used to study molecular mobility.