Solvation properties of 1-alkyl-3-methylimidazolium thiocyanate ionic liquids in the presence of lithium halide salts in N-methyl-2-pyrrolidone

Recently, ionic liquids in design and optimization of the membrane technology were applied. Thiocyanate based ionic liquids as green and fluorine-free solvents were used effectively in the preparation of membranes that were used in separation and purification. In this work, 1-alkyl-3-methylimidazolium thiocyanate, [RMIM][SCN] (R = butyl, hexyl, and octyl), were synthesized and some of the thermophysical properties of (IL + LiX (X = Cl, Br) + N-methyl-2-pyrrolidone) ternary solutions including density, speed of sound and viscosity data have been determined at T = 298.15 K. Also, the standard partial molar volumes V-phi(0), partial molar isentropic compressibility (0)(K)(phi) and viscosity B-coefficients have been calculated. The scaled particle theory (SPT) was used to determining of different contributions of the V-phi(0). The obtained quantities were used to interpret the influence of lithium halide salts on the solute-solvent interactions in the studied IL solutions. (C) 2019 Elsevier B.V. All rights reserved.