Measurement of the Density and Ultrasonic Speed of the Sound of Poly(ethylene glycols) (600 and 6000) in Aqueous Vitamin B₅ Solutions at Different Temperatures

Abstract

The present study involves measurement of the density and ultrasonic speed of sound via Anton Paar DSA 5000 M for the binary mixture of water + poly­(ethylene glycol) 600/poly­(ethylene glycol) 6000 and ternary mixture of water + d-Panthenol + poly­(ethylene glycol) 600/poly­(ethylene glycol) 6000 covering a whole range of compositions (0.00, 0.02, 0.07, and 0.12 mol kg–1) at 0.01 MPa pressure from 288.15 to 318.15 K. The volumetric properties (apparent molar volume, partial molar volume, and partial molar volume of transfer) are evaluated from the density data; meanwhile, the speed of sound data is utilized to determine the acoustic properties (apparent molar isentropic compression, partial molar isentropic compression, and partial molar isentropic compression of transfer). This investigation is further extended by calculating the partial molar expansibility with its first derivative and pair-triplet interaction coefficients from these derived thermodynamic parameters. The obtained results from these calculated parameters are expressed as solute–solvent, ion–hydrophilic, hydrophilic–hydrophilic, and dipole–dipole interactions prevailing in the liquid sample.

Thermodynamic and Physicochemical Studies of Polyethylene Glycols in Water-Soluble Tetrasodium EDTA Solution Depending on Temperatures

“…Low V ϕ values indicate that the solute molecules are well hydrated, as water molecules in the hydrogen bond structure increase the packing efficiency. In contrast, high V ϕ values demonstrate an existence for significant solute– co -solute interactions. − …”