Density and refractive index for binary systems of the ionic liquid [Bmim][BF4] with methanol, 1,3-dichloropropane, and dimethyl carbonate

Refractive indices at 298.15 K and densities in the temperature interval 293.15 to 318.15 K were determined at atmospheric pressure over the whole composition range for the binary systems [Bmim][BF4]+(methanol, or 1,3-dichloropropane, or dimethyl carbonate). Due to the high viscosity of the samples, which would produce a wrong density if a classical vibrating-tube densimeter were used, a densimeter was employed that automatically corrects the data for the viscosity effect. Because at room temperature some [Bmim][BF4]+dimethyl carbonate mixtures showed partial immiscibility, liquid-liquid equilibrium was determined for this system. Excess molar volumes and deviations of refractive index from linear mixing behavior were calculated from the experimental data.