Interaction of poly(ethylene glycol)-400 with tetraethylammonium bromide in aqueous media

The interaction between poly(ethylene glycol)-400 (PEG-400) and tetraethylammonium bromide (Et4NBr) has been investigated through density, ultrasonic velocity, viscosity, and 1H NMR measurements at 303.15 K. The concentration of PEG-400 has been varied in the aqueous media containing a fixed amount of Et4NBr (1-20 wt.%). The apparent and transfer properties including the apparent molal volume Vϕ,s, isentropic compressibility Kϕ,s, solvation number ns, and reduced viscosity ηred, respectively, have been deduced from the experimental data. The infinite dilution values of Vϕ,s and Kϕ,s of the solvated species are also estimated by extrapolation towards infinite dilution. The ultrasonic velocity shows the apparent breakdown in variation with the polymer concentration. The viscosity measurement enables to observe the concomitant reorganization of the solute species. The stoichiometry of the solvated species has been investigated by means of 1H NMR analysis.