超声波辅助法合成离子液体[C2OHmim]BF4及其双水相体系的研究

Ultrasonic-assisted Synthesis of N-(2-Hydroxyl ethyl)-3-methyl Imidazole Tetrafluoroborate Ionic Liquid and Its Application in Aqueous Two-phase System

采用超声波辅助法合成了N-(2-羟乙基)-3-甲基咪唑四氟硼酸盐([C2OHmim]BF4),产率达57.69%,并建立了[C2OHmim]BF4和无机盐形成的离子液体双水相体系。结果表明,盐的种类和浓度对体系的形成影响很大,(NH4)2SO4能与[C2OHmim]BF4水溶液形成双水相体系。在2 mL[C2OHmim]BF4与3 mL水的混合溶液中加入0.750 0 g(NH4)2SO4后,能形成稳定的双水相且相比达0.923,接近于1;在pH=6～9时,溶液酸度对体系相比的影响较小;在不同温度下体系的热稳定性较好,受温度影响不大;离子液体可再利用。

N-（ 2-Hydroxyl ethyl ）-3-methyl imidazole tetrafluoroborate （ [ C2OHmim ] BF4 ） was synthesized under the condition of ultrasound intermittent operation. The yield was 57.69%. Compared with conventional synthesis method, the reaction time was drastically reduced and a higher yield was obtained. Then, [ C2OHmim] BF4 was used in aqueous two-phase system（ATPS）. The results show that the category of salt and its concentration had significant influence on the formation of ATPS. Thermally stable ATPS can be formed under the following conditions： 2 mL [ C2OHmim] BF4,3 mL water, 0. 750 0 g （NH4 ）2 SO4- The phase volume ratio of the system was 0. 923. At pH 6 -9, the acidity of the solution had little influence on the phase volume ratio of the system. [ C2OHmim] BF4 can be reused for extraction.