An elastic neutron scattering on dynamical transition in hydrogen-bonded systems

Elastic incoherent neutron scattering measurements have been performed on trehalose and sucrose/D2O mixtures as a function of temperature. The study provides an effective way for characterizing the dynamical behaviour, furnishing a set of parameters characterizing the 'flexibility' and the 'rigidity' that justifies the better cryptobiotic effect of trehalose with respect to sucrose. Elastic scans make evident a non-Gaussian behaviour of the intensity profiles, which is more marked for sucrose, with a dynamical transition at T~253 and ~250 K for trehalose/D2O and sucrose/D2O mixtures, respectively.