We have investigated the relationship between the thermodynamic and kinetic properties of the glass transition and solvation structure for simple amine and alcohol solutions of inorganic salts by using differential-scanning calorimetry (DSC) and Raman spectroscopy. Although the glass transition temperature (Tg) increases with the addition of salts in common, the concentration dependence of the heat-capacity change (ΔCp) at Tg and the kinetic fragility index (m) are quite different for the amine and alcohol solutions. The thermodynamic and kinetic properties depend more strongly on the solvents than on the solutes. From Raman results, the structural-breaking effect of adding ions on the hydrogen-bonding structure is found to be quite different between the amine and alcohol solutions. By comparing the DSC data with the Raman results, we suggest that the glass-transition thermodynamics and kinetics are controlled mainly by the strength or stability of hydrogen-bond structures and the properties of dominant intermolecular interactions in the solutions.
Keywords:glass transition, fragility, solvation structure, hydrogen-bond, DSC
Publication Date: 2019-04-25