Volumetric, Ultrasonic and Viscometric Studies of Aspirin in the Presence of 1-Octyl-3-Methylimidazolium Bromide Ionic Liquid in Acetonitrile Solutions at T=(288.15–318.15) K

Abstract

Abstract In a continuation of previous studies, thermophysical properties of the systems containing aspirin (ASA), ionic liquid, 1-octyl-3-methylimidazolium bromide ([OMIM][Br]) and acetonitrile (MeCN) have been determined. These properties contain density, viscosity, speed of sound and refractive index measured at T=(288.15 K–318.15 K) and at atmospheric pressure. The measured data have been applied to calculate the apparent molar volumes at infinite dilution V φ 0 , $V_\varphi ^0,$ transfer volumes Δ V φ 0 , $\Delta V_\varphi ^0,$ apparent molar isentropic compressibilities κ ϕ , to viscosity B-coefficients and solvation number. The positive values of Δ V φ 0 $\Delta V_\varphi ^0$ and Δ κ φ 0 $\Delta \kappa _\varphi ^0$ indicate that dominant interactions between ASA and ionic liquid are ion–polar and polar–polar interactions. From the obtained parameters, some information in regard with the solute–solvent interactions in the studied systems was obtained. The cosphere overlap model was used to interpret the positive transfer volume Δ V φ 0 . $\Delta V_\varphi ^0.$