Thermophysical Properties of Dicationic Ionic Liquids under the Influence of Amino Acid

Abstract

Thermodynamic properties are supportive in describing the structure and properties of solutions concerning solute−solute and solute−solvent interactions. With this regard experimental values of densities (ρ), speeds of sound (u), and absolute viscosities (η) of butyl and pentyl dicationic ionic liquids (DILs) as binary [C (n) −DIL + water] and ternary [C (n) −DIL+ glycine + water] systems where (n = 4, 5) have been studied at different temperatures at T = (293.15−313.15 K). The densities of DILs decrease with the increase in alkyl chain length having imidazolium cations with the rise in temperature. It may be due to the bulkiness of the longer alkyl chains preventing them from efficient close packing leading to a decrease in the density. The molecular interactions are discussed in terms of apparent molar volume (V ϕ ), apparent molar isentropic compressibility (κ ϕ ), Jones−Dole coefficient of viscosity supported with the partial molar volume of transfer (Δ tr V ϕ 0 ), partial molar compressibility of transfer (Δ tr κ ϕ 0 ) and transfer values of B coefficient of DILs from water to 0.06 mol•kg −1 aqueous systems of glycine. These structural interactions for studied DILs−glycine pairs in water have been also discussed and interpreted by thermal study and electrochemical study.