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Theinteractions of amino acids + water + 1-ethyl-3-methylimidazoliumchloride [emim][Cl] solutions have been studied at different temperaturesusing volumetric and acoustic measurements. The density (ρ)and speed of sound (u) of glycine/l-alanine/l-valine + water + 1-ethyl-3-methylimidazolium chloride solutionshave been measured at temperatures T= (288.15, 293.15,298.15, 303.15, and 308.15) K and experimental pressure of 0.1 MPa.The apparent molar properties, standard partial molar properties,and partial molar properties of transfer have been determined fromexperimentally measured densities and speeds of sound. The resultingvalues of Vϕ0, ΔVϕ0, Kϕ,s0, and ΔKϕ,s0have been used to discuss the nature of interactions presentin the mixtures. The apparent molar expansivity ϕE0and its temperaturederivative (∂ϕE0/∂T) have also beencalculated. [ABSTRACT FROM AUTHOR]

Knowledge of thermodynamic properties of amino acids in aqueous medium can provide valuable information about the stabilization mechanism of proteins. In this study, we report the density and speed of sound of some amino acids (2-aminopropanoic acid, 2-amino-3-methylbutanoic acid, 2-amino-4-methylpentanoic acid, and 2-amino-3-phenylpropanoic acid) in aqueous fructose, d-()-cellobiose, and d-melezitose solutions (0.1 mol·kg−1) at (293.15, 298.15, 303.15, and 308.15) K. From these data, the apparent molar volume and apparent molar adiabatic compressibility have been evaluated. The partial molar volume, partial molar adiabatic compressibility, and their corresponding transfer functions were calculated. These results were used to interpret the type of interactions occurring in the ternary mixtures using the cosphere overlap model. The concentration and temperature dependence of solute−solute and solute−solvent interactions in the present study was also discussed. [ABSTRACT FROM AUTHOR]

The densities, ρ, and the speeds of sound, u, for binary liquid mixtures containing 2-(2-hexyloxyethoxy)ethanol (C 6E 2) and n-butylamine (BA), dibutylamine (DBA), and tributylamine (TBA) have been measured as a function of composition using a vibrating tube densimeter and sound analyzer Anton-Paar model DSA-5000 at temperatures (288.15, 293.15, 298.15, 303.15, and 308.15) K and atmospheric pressure. The ρ and uvalues were used to calculate excess molar volumes, VmE, and excess molar isentropic compressibility, KS,mE, respectively. The VmEand KS,mEvalues are shown to be negative for all the mixtures over the entire composition range. Both VmEand KS,mEbecome more negative for all the mixtures with the rise of temperature. The change of VmEand KS,mEwith composition and temperature are discussed with a view to understand molecular interactions present in alkoxyethanol-alkylamine mixtures. [ABSTRACT FROM AUTHOR]