A study of the molecular motion in glucose/water mixtures using deuterium nuclear magnetic resonance

Publisher Website
Google Scholar
Abstract
Using separate samples containing deuterated glucose and D 2 O , the motions of the glucose and the water molecules in the viscousliquid and in the amorphousglass phase of glucose/water mixtures are examined. Spin-lattice relaxation measurements and spectra obtained in the solid confirm the existence of both a crystalline ice phase and an amorphousglass phase. Diffusion measurements performed using the large gradient in the fringe field of a superconducting magnet determine the rates of translational motion of both the sugar and the water molecules over a limited range of temperature in the viscousliquid region. From the deuterium nuclear magnetic resonance spin-lattice relaxation time, T 1 , the spin-spin relaxation time, T 2 , and spin-alignment measurements, correlation times for the motion of these molecules are obtained. The correlation time for the α process increases dramatically at T g , while the β process continues into the low temperature glass phase, following an approximately Arrhenius relationship.