The effects of ionic liquid mixtures on the phase behavior of azeotropic mixture of acetonitrile + water were presented through the experimental determinations of isobaric vapor-liquid equilibrium for acetonitrile + water + 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF₄]) and acetonitrile + water + 1-butyl-3-methylimidazolium chloride ([Bmim][Cl]) + [BMIM][BF₄] at atmospheric pressure (101.3 kPa). The mole ratios of [BMIM][Cl] to [BMIM][BF₄] in the mixing ILs were fixed at 2:1, 1:1 and 1:2, respectively. The results showed that [BMIM][BF₄] was ineffective in breaking the azeotropy of acetonitrile and water, which whereas could be broken when [BMIM][Cl] reached a certain concentration in the mixing ILs. VLE data of ternary and quaternary mixtures were satisfactorily correlated and predicted with NRTL model and COSMO-SAC could give a reasonable prediction of VLE for the investigated mixtures. Additionally, the analysis of interactions among different molecules showed that the interactions between [BMIM][Cl] and water are strong while ones between [BMIM][BF₄] and water weak.

通过实验确定乙腈+水+ 1-丁基-3-甲基咪唑四氟硼酸酯（[BMIM] [BF ₄ ] ）和乙腈+水+ 1-丁基-3-甲基咪唑鎓氯化物（[Bmim] [Cl]）+ [BMIM] [BF ₄ ]在大气压（101.3 kPa）下进行。混合IL中的[BMIM] [Cl]与[BMIM] [BF ₄ ]的摩尔比分别固定为2∶1、1∶1和1∶2。结果表明，[BMIM] [BF ₄]不能有效地破坏乙腈和水的共沸性，而当[BMIM] [Cl]在混合离子液体中达到一定浓度时，它可能被破坏。用NRTL模型对三元和四元混合物的VLE数据进行了令人满意的关联和预测，而COSMO-SAC可以为所研究的混合物提供合理的VLE预测。另外，对不同分子间相互作用的分析表明，[BMIM] [Cl]与水之间的相互作用较强，而[BMIM] [BF ₄ ]与水之间的相互作用较弱。