Computer Simulation Of Room Temperature Ionic Liquid System

Room temperature ionic liquids (RTILs) are a class of organic salts that remain liquid at or near room temperature, usually composed of organic cations and organic or inorganic anions. Compared with traditional organic solvents, RTILs have tremendous advantages, such as negligible vapor pressure, good solvation ability for organic or inorganic materials, and having the function of both solvent and catalyst. Furthermore, through different combinations of cations and anions, there is a tremendous variety of "designer" solvents. Their status as "green" or "designer" solvents explains the large amount of studies concerning their possible industrial use as reaction or extraction media.To test the force field of RTILs proposed by our group (J. Phys. Chem. B, 2004, 108, 12978-12989), thermodynamic properties of the mixture of [bmim][BF₄] (1) + acetonitrile (2) were investigated by molecular dynamics simulations. The calculated densities are in good agreement with the experimental data, with absolute relative deviations (ARD) less than 2%. The excess molar volumes are negative over the whole concentration range and present a minimum at [bmim][BF₄] mole fraction of 0.3, which coincides with the phenomenon from experiment. The Self-diffusion coefficients of the mixture were estimated by using those of three components. Furthermore, the viscosities of the mixture were estimated by...