Apparent molar volume and apparent molar isentropic compressibility for the binary systems {methyltrioctylammoniumbis(trifluoromethylsulfonyl) imide + ethyl acetate or ethanol} at different temperatures under atmospheric pressure

摘要

The density (d) and speed of sound (u) for the binary systems were measured at 298.15, 303.15, 308.15, and 313.15 K under atmospheric pressure. The binary systems contained the ionic liquid (IL): methyltrioctylammoniumbis(trifluoromethylsulfonyl)imide ([MOA] ~+[Tf_2N].). The binary systems were ([MOA] ~+[Tf_2N]. + ethyl acetate or ethanol). The apparent molar volume, V_φ, and the apparent molar isentropic compressibility, k_φ, have been evaluated from the experimental density and speed of sound data, respectively. A Redlich.Mayer equation was fitted to the apparent molar volume and apparent molar isentropic compressibility data. The partial molar volume, V~0 _φ., and partial molar isentropic compressibility, k~0_φ., of the binary mixtures have also been calculated at each temperature. The partial molar volume indicates that the intermolecular interactions for (IL + ethanol) are stronger than for (IL + ethyl acetate) at all temperatures and V~0_φ. for both systems increases with an increase in temperature. The values of the infinite dilution apparent molar expansibility, E~0_φ., decreases with an increase in temperature. The isentropic compressibilities, k_s, increases with an increase in temperature for both binary systems. Positive k~0_φ., for both binary systems can be attributed to the predominance of solvent intrinsic compressibility over the solute intrinsic effect.