Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

ABSTRACT

The apparent molar volume oVpoundsP and isentropic compression oKpounds;sP of glycine, L-alanine and L-valine have been studied in (0.025, 0.05, 0.075 and 0.1) mol kg 1 aqueous 1-butyl-4-methyl pyridinium chloride o1/2C4mpy ClP solutions over a range of temperatures (288.15, 293.15, 298.15, 303.15 and 308.15) K from the values of densities (q) and ultrasonic speed (c), repectively. The standard partial molar volumes oV0 pounds P, standard partial molar isentropic compression oK0 pounds;s P, and experimental slopes (SV and SK) have been determined for these amino acid solutions from the Masson equation and have been interpreted in terms of solute-solvent and solute-solute interactions, respectively. The hydrophilic-hydrophilic, hydrophilichydrophobic and hydrophobic-hydrophobic interactions are involved in the studied systems of 1/2C4mpy Cl + amino acids + H2O by calculating the corresponding transfer functions oDV0 poundsandDK0 pounds;s P. The contribution of the charged end groups oNHp 3 ; COO P, o CH2P group and other alkyl chains of the amino acids were estimated using V0 pounds values. Hydration number onHP for studied amino acids in aqueous 1/2C4mpy Cl solutions are positive, which suggest a strong dehydration effect of 1/2C4mpy Cl. The obtained parameters will be helpful to understand mixing effects and other complex biological processes between head and side chain group of amino acids and ionic liquid 1/2C4mpy Cl in aqueous solution.