Fragile-like behaviour and H-bond interactions of the glass-forming water—trehalose system

In this work the results obtained by means of ultrasonic, viscosity and Raman measurements on trehalose—water solutions, are presented. The ultrasonic data show that the mixing process is not ideal and that the water—trehalose interaction strength, because of the saturation of H-bond sites, decreases on increasing the concentration. Furthermore, the temperature behaviour of the shear viscosity in a strong—fragile pattern, and the analysis of depolarized Raman scattering spectra, relative to the supercooled region, demonstrate the noticeable kinetically fragile character of these systems. Additional features are discussed in the framework of current theories.