電解質溶液における溶媒分子の縦緩和時間に対する温度および圧力効果

抄録

To elucidate the effect of ions on the solvent structures in view of the dynamics of solvent molecules, the spinlattice relaxation times (T₁) of solvent molecules (D₂O and DMSO) in various electrolyte solutions were measured in a relatively wide range of temperature under atmospheric pressure, and those of D₂O at moderate temperature under high pressure. From the behaviors of rotational correlation times (τ_c) and their activation energies (E_a) of solvent molecules (D₂O) hydrated to the ions, the ions are classified into structure-making and structure-breaking ions. These characteristics obtained in aqueous solutions were compared with those in non-aqueous solutions (DMSO). Finally the pressure effects on τ_c in D₂O solutions are discussed focusing on the pressure dependence of the hydrophobic hydration.