离子液体[BPy]BF_4和甲醇二元混合体系的超额摩尔体积、折射率和黏度  

Excess Molar Volume,Refractive Index and Viscosity of N-Butylpyridinium Tetrafluoroborate Ionic Liquid+Methanol Binary System

作　　者：许映杰[1,2] 黄钗英[1] 李浩然[2] 

机构地区：[1]绍兴文理学院化学化工学院,浙江绍兴312000 [2]浙江大学化学系,浙江杭州310027

出　　处：《高校化学工程学报》2011年第3期370-375,共6页Journal of Chemical Engineering of Chinese Universities

基　　金：浙江省自然科学基金(Y4090453);绍兴文理学院校级重点科研项目

摘　　要：合成了室温离子液体N-丁基吡啶四氟硼酸盐([BPy]BF4),通过核磁共振1H-NMR和红外光谱IR对其结构进行了表征。在298.15 K和常压下,采用U形振荡管密度计测定[BPy]BF4-甲醇体系的密度;用阿贝尔折射仪测定了该二元混合体系在相同温度和压力下的折射率;用乌氏黏度计测定了该二元混合体系在相同温度和压力下的黏度,并由密度数据计算出超额摩尔体积(V E)、由折射率数据计算出了折射率改变值(△nD)、由黏度数据计算出了体系的黏度B系数。结果表明:[BPy]BF4-甲醇体系的V E在全浓度范围内为负值,而△nD在全浓度范围内为正值,两者均在摩尔分数x1≈0.4处出现极值;采用Redlich-Kister方程对V E、△nD与组成的关系进行了关联,最大标准偏差小于3%,说明此方程可适用于回归该二元体系上述的物性数据。由Jones-Dole方程计算出体系的黏度B系数为0.35608,这表明甲醇有效地降低了离子液体的黏度。Room temperature ionic liquid N-butylpyridinium tetrafluoroborate（BF4） was synthesized,and its structure was characterized and confirmed by 1H-NMR and IR.The densities and refractive indices of binary mixtures（BF4＋methanol） with different compositions were determined at T = 298.15 K and under atmospheric pressure by using a vibrating U-shaped sample tube densimeter and semi-automatic refractometer,respectively.The viscosities of the mixtures were also determined at T = 298.15 K and under atmospheric pressure by using Ubbelohde Suspended-level viscometer.Density values were used in the calculation of the excess molar volumes（V E）,and the refractive indices were used to calculate the changes of refractive index（△nD）.The achieved viscosities were used to calculate the viscosity B coefficient of the mixtures.The results show that the values of V E are negative over the entire composition range,while the △nD are positive.When the mole fraction of BF4 is about 0.4,both the values of V E and △nD have extreme point.V E and △nD were correlated with Redlich-Kister equation,respectively,and both the standard deviations are lower than 3%.The results indicate that the Redlich-Kister equation can be used to correlate the two mentioned physical properties of this system well.The viscosity B coefficient of the mixtures was calculated by Jones-Dole equation,and its value is 0.35608,which indicates that the methanol effectively reduces the viscosity of ionic liquids.

关 键 词：四氟硼酸正丁基吡啶 离子液体 密度 黏度 折射率 超额摩尔体积 折射率改变值 

分 类 号：O645.164[理学—物理化学]