文摘
The effect of C2鈥揌 of alkylimidazolium tetrafluoroborate ionic liquids on the interaction and vapor鈥搇iquid equilibrium (VLE) of the ethyl acetate + ethanol mixture was studied using spectroscopy and the COSMO-RS method. Concentration-dependent 1H NMR chemical shifts of ethyl acetate + ethanol + [Bmim]BF4 or [Bmmim]BF4 (xIL = 0.1 and 0.3) systems show that the interaction between [Bmim]BF4 and ethanol is much stronger than that between [Bmmim]BF4 and ethanol. Moreover, the experimental and predicted VLE demonstrate that the improvement of relative volatility of ethyl acetate to ethanol by [Bmim]BF4 is better than that by [Bmmim]BF4. Also, 蟽-profile obtained from COSMO-RS method indicates that the hydrogen bonding donator ability of [Bmim]+ is greater than that of [Bmmim]+. Therefore, it can be deduced that the acidic C2鈥揌 plays an important role in the interaction differentiation of the ionic liquids and their effect on the VLE of the ethyl acetate + ethanol system, resulting from the interaction of the acidic C2鈥揌 with the ethanol that is much stronger than with the ethyl acetate.