Photo-acoustic and ultrasonic investigation of the mixtures of water and several glycols

Authors:

• Wioletta Zwirbla,
• Ewa Barbara Skrodzka,
• Bogumił B. Linde

Abstract

In the paper the results of the ultrasonic velocity and absorption measurements were presented, as well as the thickness in water mixtures of some glycols. The experiments were provided in the temperature range from 291.15 to 303.15 K for whole molar fraction. Adiabatic compressibilities were calculated from Laplace's equation based on the experimental results obtained. Variations of these values with concentration and temperature were studied. Structural interactions and the formation of a compact pseudostable structure at very low concentrations of ethylene glycol and polyethylene glycols were observed. The plots of the adiabatic compressibility versus the mole fraction of PEG and EG display two characteristic points at low concentrations: the intersection of the isotherms and their minimum. Such relations between adiabatic compressibility, concentration and temperature are usually attributed to the formation of pseudo-stable molecular structures. To formulate a model of local structures present in the investigated molecular systems it is indispensable to get an insight into hydration of molecules and the formation of hydrogen bonds. © 2013 Acoustical Society of America.