一个物理化学设计实验的探讨与改进——离子液体溶液平均活度系数的测定

Exploration and Improvement of the Physical Chemistry Design Experiment-the Determination of the Average Activity Coefficient of Ionic Liquid Solution

文章制备了溴化1-十二烷基-3-甲基咪唑[C12mim]Br和1-十二烷基-3-甲基咪唑四氟硼酸盐[C12mim][BF4]两种离子液体。在不同温度下,测定了两种离子液体水溶液的电导率,根据电导率-浓度曲线转折点求出了两种离子液体水溶液的临界胶束浓度。由Debye-Hücker和Osager-Falk-enhangen公式计算出离子液体的平均活度系数。结果表明:[C12mim]Br和[C12mim][BF4]的水溶液临界胶束分别为5.75×10-3 mol·L-1和6.00×10?3 mol·L-1。25℃下,平均活度系数随浓度的增大而降低。

In the thesis,[C12mim] Br and [C12mim] have been prepared.The electrical conductivity of ionic liquid aqueous solutions was determined at different temperatures.The critical micelle concentration was obtained according to conductivity-a turning point in the concentration curves.The average activity coefficient of the two ionic liquid at 25 ℃ was calculated by the Debye-Hücker and Osager-Falkenhangen formulas.The results show that the critical micelle concentration of [C12mim]Br and [C12mim] respectively were 5.75×10-3 mol·L-1 and 6.00×10-3 mol·L-1 at 25 ℃.The average activity coefficient decreases with the concentration increasing.