Effect of L-Arginine on Electrical Conductances of Aqueous Ionic Liquids 1-Alkyl-3-methylimidazolium Bromide Solutions at T = 298.15 K

Electrical conductances of aqueous ionic liquids, 1-propyl-3-methylimidazolium bromide, 1-butyl-3-methylimidazolium bromide, 1-pentyl-3-methylimidazolium bromide, 1-hexyl-3-methylimidazolium bromide solutions in dilute region in the presence of amino acid, L-arginine, have been measured at T = 298.15 K. The ion association constants, KA, limiting molar conductivities, 0 ? and distance parameters, R were obtained using low concentration Chemical Model (lcCM) conductivity equation for the investigated ionic liquids. The results show that the KA value and limiting molar conductivity, ?0 decrease with increasing L-arginine concentration and lengthening alkyl chain of ionic liquids. Therefore, there is slight ion association effect in [HMIm]Br. This can be attributed to the interaction of [RMIm]Br with the amino acids and increasing viscosity of mixture.