Solute–solvent interactions of ibuprofen in the aqueous solutions of 1–propanol: Volumetric, acoustic and viscometric study

Abstract

Ternary system contains ibuprofen + water +1–propanol in the certain composition have been reported as forming two phases systems. Therefore solute–solvent and solute–solute interactions are necessary for a fundamental understanding of the phase equilibrium in this ternary system. In this work solute–solvent and solute–solute interactions were studied via volumetric, acoustic and viscometric methods. The experimental densities, speed of sounds and viscosities of ibuprofen in mixtures of water +1–propanol with different cosolvent proportions (w1-pro = 1.000, w1-pro = 0.950, w1-pro = 0.900, w1-pro = 0.850, w1-pro = 0.800) were measured at temperatures T = 288.15, 298.15 and 308.15 K. The apparent molar volume (Vϕ), apparent molar volume at infinite dilution (Vϕo), apparent molar volume of transfer (ΔtrVϕo), apparent molar isentropic compressibility (κϕ), apparent molar isentropic compressibility at infinite dilution (κϕo) and viscosity B-coefficient were calculated using the experimental data. The obtained apparent molar volume, apparent molar isentropic compressibility at infinite dilution and viscosity B–coefficient are explained in terms of solute–solvent and solute–solute interactions. The obtained results reveal that solute–solvent interactions decrease with increasing temperature. Also, solute–solvent interactions decrease with decreasing weight fraction of 1–propanol. This behavior may be due to preferential solvation of ibuprofen with 1–propanol.