Johari-Goldstein process of solute in high-water-content aqueous solutions

For low-water-content aqueous solutions, the primary \ensuremath{\alpha} process due to the cooperative motion of solute and water molecules and the secondary Johari-Goldstein (JG) process of solute are observed. For high-water-content aqueous solutions, the \ensuremath{\alpha} process due to the cooperative motion of solute and water molecules and the secondary \ensuremath{\beta} process due to the motion of excess water are observed. However, the JG process of solute has not been observed. To clarify this difference, we measured the dielectric spectra of supercooled triethyleneglycol-water mixtures in a wide temperature range. We discuss the effect of excess water on the molecular dynamics relating to the JG process of solute in high-water-content aqueous solutions.