Acoustical and volumetric investigation of polyethylene glycol 400 and polyethylene glycol 4000 in aqueous solutions of glycerol at different temperatures

The intermolecular interactions of glycerol with two polyethylene glycols i.e. polyethylene glycol 400 and polyethylene glycol 4000 in aqueous medium have been examined from the measurements of density and ultrasonic speed at temperatures T = (293.15, 298.15, 303.15, 308.15) K and experimental pressure p = 0.1 MPa. The apparent molar volume (Vϕ), partial molar volume (Vϕo) and partial molar volume of transfer (ΔVϕo) have been evaluated from density data for polyethylene glycols from water to aqueous glycerol solutions. The limiting apparent molar expansibilities have also been evaluated. The ultrasonic speed measurements are used to determine apparent molar isentropic compression (Kϕ,s), partial molar isentropic compression (Kϕ,so) and partial molar isentropic compression of transfer (ΔKϕ,so) for polyethylene glycols from water to aqueous glycerol solutions. From (partial molar volume and partial molar isentropic compression) of transfer, the pair and triplet coefficients are calculated. By the perusal of these determined parameters, the results have been explicated based upon the competing patterns of physicochemical interactions of co-solutes and the solvents.