[Epy]BF_4-(NH_4)_3C_6H_5O_7-H_2O双水相体系液液相平衡测定及其关联

Studies on Liquid-Liquid Equilibrium of an Aqueous Two-Phase System [Epy]BF_4-(NH_4)_3C_6H_5O_7-H_2O

实验测定了298.15K,离子液体N-乙基吡啶四氟硼酸盐([Epy]BF4)与(NH4)3C6H5O7形成的双水相体系的液液相平衡数据。采用三个经验方程对得到的双节线数据关联,实验得到的双水相体系的系线数据,利用Setschenow-type方程进行关联,关联结果较为满意。利用双节线模型,计算了该体系的有效排除体积(EEV)。结果表明,双水相体系上相富含[Epy]BF4,下相则富含(NH4)3C6H5O7,该体系既能用于萃取分离,也可以用于从水溶液中分离回收离子液体。

Liquid-liquid equilibrium properties of the N-ethyl pyridine four fluorine boric acid salt （[Epy]BF4）＋ tribasic Ammoniumcitrate （（NHa）3C6HsOT） aqueous two-phase system at T=298.15K was studied. Threeempirical equations were used to correlate the binodal data obtained and the Setschenow-type equation was usedto correlate the tie-line data. The results show that good agreements can be obtained with the experiment data.Moreover, the system effective excluded volume （EEV） was calculated by the binodal model. The experimentalresults show that the top and bottom phases of the system are mainly composed of [Epy]BF4 and（NH4）3C6H507, respectively. This study shows that the system studied can be used not only for extraction andseparation, but also in primary separation and recovery of ionic liquids from aqueous solutions.