Densities, Viscosities, Electrical Conductances, and Refractive Indices of Amino Acid plus Ionic Liquid ([BMIm]Br) Water Mixtures at 298.15 K

Densities, viscosities, electrical conductances, and refractive indices of the amino acids glycine, L-alanine, and L-valine in aqueous ionic liquid, 1-buty1-3-methylimidazolium bromide ([BMIm]Br), solutions have been measured at 298.15 K. These data have been used to calculate apparent molar volumes, V-phi, viscosity B-coefficients and ion association constants, K-a, for the mixtures studied. The limiting partial molar volumes, V-phi(0) and transfer partial molar volumes, Delta V-tr(phi)0 have been determined. It has been observed that both V-phi(0) and Delta V-tr(phi)0, values for amino acids increase with increasing ionic liquid concentrations. The linear correlation of V-phi(0) and B-coefficient values with the number of carbon atoms in alkyl chain of the amino acids have been used to estimate the contribution of charged end groups (NH3+, COO-). All these parameters was used to interpretate solute solvent interactions occurring between the various components in these ternary mixtures. Limiting molar conductivities, Lambda(0) and ion association constants, K-a of ionic liquid were obtained from the low concentration chemical model (IcCM) of the conductance equation.