Molecular simulations of imidazolium-based ionic liquids with [ l-lactate] − anion and the binary mixture of [bmim][ l-lactate] and 1-octanol

Abstract

In this work, molecular dynamics simulations were performed for pure 1-alkyl-3-methyl-imidazolium-based ionic liquids with [ l-lactate] − anion and the binary mixture of [bmim][ l-lactate] + 1-octanol using a united-atom force field. For the pure ionic liquids, the densities, molar volumes, enthalpies of evaporation, cohesive energies, standard entropies, lattice energies, microstructures, and self-diffusion coefficients were studied. It was found that the simulated densities agreed well with experimental values. In addition, the strong interactions between cation and anion were also found in simulations. The effects of the alkyl chain length in cation on the thermophysics, structures, and transport properties of ionic liquids were further discussed. For the mixtures, many volumetric properties, such as excess molar volume, partial molar volume, excess partial molar volume, and apparent molar volume, were calculated. The effects of the molar fractions of ionic liquid on the properties of the binary mixture of [bmim][ l-lactate] + 1-octanol were also studied. The 1-octanol weakened the strength of interactions of cation and anion of ionic liquids in the mixture.