Hydrophobic-like solvation in non-aqueous solutions: Positron annihilation in and compressibility of n-hexanol in ethylene glycol, 1,2-butanediol and 1,4-butanediol

Abstract

The results of positron annihilation experiments of solutions of n-hexanol in diols are compared to those of ultrasonic velocity and absorption. Variations of the annihilation parameters with composition allow the conclusion that the effect of hydrophobic solute on the original diol structure is limited. There are, however, significant similarities with the results known for aqueous systems, suggesting that clathrate-like solvates are forming in ethylene glycol, the phenomenon called here is a hydrophobic-like solvation. No evidences for it were found for the systems containing butanediols as solvents. Unfortunately, ultrasonic investigations do not confirm the formation of any specific structures, most possibly because the compressibilities of solvates are close to those of the pure components.