Dielectric relaxation of aqueous solutions of maltotriose

Abstract

The molecular motions in two aqueous maltotriose solutions with different weight fractions (85% and 50%) were investigated by the dielectric relaxation and differential scanning calorimetry. The 85% solution shows two relaxation modes with the different frequency and temperature dependences in the dielectric relaxation curves. The lower frequency mode is due to the hydrated maltotriose. This mode strongly depends on temperature, indicating the structural relaxation of the solution. The higher frequency mode shows an Arrehnius type of temperature dependence ascribed to the hydrated water molecules. The 50% maltotriose solution has another relaxation mode of ice Ih crystal in addition to these relaxation modes. The temperature dependences of both solutions were compared to interpret the molecular motions on the basis of the phase behaviors.