Yukio Terashima

Effects of solvents and solutes on glass-transition thermodynamics and kinetic fragility for amine and alcohol solutions of inorganic salts

We have used differential scanning calorimetry (DSC) to investigate the thermodynamic and kinetic properties of the glass transition of simple amine and alcohol solutions of inorganic salts. Although the glass-transition temperature (Tg) increases with the addition of salts, in common with other solutions, the concentration dependence of the heat-capacity change (∆Cp) 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. By comparing the DSC data with 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.

Laminated Specimens of Polystyrene Foams for Microscopic Observation of Two-Dimensional Structure

We developed a teaching material for a microscopic observation of two-dimensional structure of polystyrene foams. The specimen is made with a thin slice of polystyrene foam laminated in between polyethylene terephthalate films. Using this teaching material, we practiced a series of learning activities for high school students to study structure and physical properties of polystyrene foams. Based on their learning, we conclude this teaching material is useful for understanding physical properties of foams in relation to everyday life and products at high school science classes.