Thermally stimulated depolarization currents in a polyzwitterion: an example of chemical relaxation

The thermally stimulated depolarization current technique is used in the case in which a temperature-dependent equilibrium between two conformational isomers of different polarities can take place. If the relaxation times involved in this reaction are smaller than the orientational relaxation time, two positive peaks and one negative peak may appear. Unlike classical thermally stimulated depolarization, the low-temperature depolarization peak can become stronger at lower polarization temperatures. Equilibrium and rate constants of the reaction at various temperatures as well as the dipole moment can be determined. An illustration of the theory is given for a polyzwitterion with μ=25 Debyes for the extended sulfopropylbetaine group