Ultrasonic and spectroscopic investigations of molecular interactions in binary mixture of PEG-400 and DMSO at different temperatures

Abstract

In the present study, the ultrasonic velocity and density data for the binary mixture of polyethylene glycol (PEG)-400 and dimethyl sulfoxide (DMSO), at various concentrations and different temperatures (T, 288.15, 298.15 and 308.15 K), have been measured and further apllied to determine several physical parameters such as adiabatic and isothermal compressibility, intermolecular free length, internal pressure and free volume. The excess values of these parameters have also been computed and fitted with the Redlich– Kister (R–K) polynomial equation. The nature, type, and strength of intermolecular interactions present within the PEG-400 + DMSO mixture have been explained based on the sign and magnitude of excess values. Furthermore, partial molar volumes, excess partial molar volumes, apparent molar volumes and apparent molar volumes at infinite dilution have also been determined to investigate the solute–solvent interactions. Various mixing rules such as the ideal mixing rule (Uim), Nomoto relation (UN), impedance dependence relation (UZ), Junjie relation (UJ), van Deal–Vangeel relation (UV) and collision factor theory (UCFT) are employed to compute the ultrasonic velocity and compared with the experimental one. Among these relations, the Nomoto and Junjie relations are found to be most suitable for the given mixture. In addition to it, the present system has also been examined using Fourier transform infra-red (FTIR) and UV–Vis spectroscopic techniques. The change in intensity and shift in peak position in the FTIR and UV–Vis spectra of the PEG-400 + DMSO mixture are used to confirm the intermolecular hydrogen bonding in the given system.

Keywords

• research development
• industry
• sustainable development
• polyethylene glycol
• fourier transform infra-red (ftir)
• uv–vis