咪唑离子液体对CsCl溶解度的影响

Influence of Imidazolium Based Ionic Liquids on Solubility of CsCl

采用密度-折光率联立法研究了稀碱金属无机盐氯化铯在咪唑离子液体[Cnmim]Br(n=2,4,6,8)和水的混合溶剂中的溶解行为。测定了在T=(288.15,298.15和308.15)K温度下CsCl+[Cnmim]Br(n=2,4,6,8)+H_2O三元体系不同组成比例下溶液的折光率和密度数据,通过关联密度和折光率数据获得了CsCl维持[Cnmim]Br(n=2,4,6,8)水相的最高浓度。研究结果表明:当在[Cnmim]Br(n=2,4,6,8)水溶液中添加氯化铯,混合系统发生复分解反应,析出固体Cs Br。相同温度下,饱和溶液中氯化铯的最大含量会随着离子液体含量的增加而降低。离子液体含量相同时,混合溶液中CsCl的最高浓度随着离子液体侧链的增长而增加,CsCl含量顺序:[C_2mim]Br<[C_4mim]Br<[C_6mim]Br<[C_8mim]Br。同一体系中,CsCl饱和浓度随着温度的升高而增大。同时,采用经验方程对CsCl饱和浓度进行了拟合,拟合结果较好。此外还测定了饱和溶液的密度及折光率数据,为描述溶液物理性质和组分之间的关系提供基础数据。

Dissolution behavior of cesium chloride in the mixture of imidazolium based ionic liquids（ [Cnmim]Br（ n = 2,4,6,8））and water was studied by density and refractive index simultaneous method. The density and refractive index of CsCl ＋ [Cnmim]Br（ n = 2,4,6,8） ＋ H2 O ternary systems with different component were measured at T =（ 288. 15,298. 15 and 308. 15） K. The highest concentration of CsCl in [Cnmim]Br（ n = 2,4,6,8） aqueous phase was obtained by correlating the density and refractive index data. The results indicated that the precipitation of cesium bromide was found in [Cnmim]Br（ n = 2,4,6,8） aqueous solution when adding cesium chloride. The complex decomposition reaction occurred in the system. The highest concentration of CsCl in the saturated solution decreased with the increasing of ionic liquid concentration at the same temperature. For a constant mass fraction of ionic liquid,the order of the highest concentration of CsCl in [Cnmim]Br（ n = 2,4,6,8） ＋ H2O mixtures was [C2mim]Br 〈[C4mim]Br 〈[C6mim]Br 〈[C8mim]Br. Furthermore,the concentration of CsCl in saturated solutions increased with the system temperature increasing. The empirical equation was used to fit the concentration of CsCl in saturated solutions. It was found that empirical equation could qualitatively represent the equilibrium behavior. In addition,the density and refractive index of the saturated solutions were determined for describing the relationship between the physical property and the solution composition.