Densities and electrical conductances of amino acids plus ionic liquid ([HMIm]Br) + H2O mixtures at 298.15 K

作者：Shekaari Hemayat^*; Jebali Fatemeh

来源：Fluid Phase Equilibria, 2010, 295(1): 68-75.

DOI：10.1016/j.fluid.2010.04.002

• Apparent molar volume
• Ionic liquid
• Amino acids
• Ion association constant

Densities and electrical conductances of amino acids, glycine, L-alanine and L-valine in aqueous ionic liquid, 1-hexyl-3-methylimidazolium bromide ([HMIm]Br) solutions have been measured at 298.15 K. These data have been used to calculate the apparent molar volumes V-phi, infinite dilution apparent molar volumes V-phi(0) and the standard partial molar volumes of transfer Delta(0),V-phi(0) of the amino acids from water to the aqueous ionic liquid solutions. It has been observed that both V-phi(0) and Delta(n),V-phi(0) in the glycine + [HMIm]Br + H2O system increases with increasing ionic liquid concentrations and decrease in the cases L-alanine and L-valine systems. The contribution of the charged end groups (NH3+, COO-), CH2 group and other alkyl chain of the amino acids was estimated using V-phi(0) values. Molar conductivities of [HMIm]Br in aqueous amino acids solutions have been applied for determination of association constants K-a. and limiting molar conductivies Lambda(0), using the low concentration chemical model (IcCM) of conductance equation.

• 出版日期2010-8-15