TEMPERATURE-DEPENDENCE OF VISCOSITY AND SPIN-LATTICE RELAXATION OF SOME HYDRATE MELTS

In this study some hydrate melts have been examined. A simple dependence of the viscosity upon the temperature has been developed in terms of free-volume theory. This relationship describes very well the non-Arrhenius behaviour of those salts. The proton-spin lattice relaxation time T 1, as a function of the temperature, has been also measured. It has been found that the temperature T* at which T 1 reaches a minimum is related to the glass-transition temperature T 0 by exp [K/(T*-T 0 )]/T 1/2*=σ, or exp [γυ*/υ f *]/T 1/2*=σ, where σ is dependent on the considered substance and on the radiofrequency. These equations mean that T* is strictly related to the glass-transition temperature T 0 or to the free volume υ f * at temperature T*. The relations between these parameters have been experimentally verified. © 1969 Società Italiana di Fisica.