Phase Separation in Solutions of Room Temperature Ionic Liquids in Hydrocarbons
Phase Separation in Solutions of Room Temperature Ionic Liquids in Hydrocarbons
复制标题
室温离子液体在碳氢化合物溶液中的相分离
DOI：
10.1524/zpch.2006.220.10.1417
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
W. Schröer
中科院分区：
文献类型：
--
作者：
D. Saracsan;C. Rybarsch;W. Schröer
室温离子液体(RTIL)、三己基十四烷基氯化膦(P66614Cl)和溴化物(P66614Br3)均可溶于碳氢化合物。所研究的溶液在正庚烷、辛烷、正庚烷和正庚烷中表现出液-液相分离，在室温下，摩尔分数接近0.03的盐有一个较高的临界溶点。报告并分析了假设伊辛临界性的相图。临界温度和临界密度随着碳氢化合物链长的增加而增加，其中溴化物的临界温度和临界密度高于氯化物。根据临界数据的比例，相图显示了相应的状态行为。约束原始模型(RPM)是介电连续介质中等尺寸带电硬球的模型流体，根据该模型的预测，当使用该模型的相应状态变量时，临界点位于低温和低浓度。然而，临界温度T_c*和临界密度ρ_c*远低于RPM预测值。并与咪唑离子液体醇溶液相图和RPM模拟结果进行了比较。
The room temperature ionic liquids (RTIL) trihexyl-tetradecyl phosphonium chloride (P666 14Cl) and the bromide (P666 14Br) are soluble in hydrocarbons. The investigated solutions in heptane, octane, nonane and decane show liquid–liquid phase separation with an upper critical solution point at ambient temperatures at molar fractions near 0.03 of the salt. Phase diagrams are reported and analysed presuming Ising criticality. The critical temperatures and the critical densities increase with the chain length of the hydrocarbons, where the figures corresponding to the bromides are above that of the chlorides. Scaled by the critical data the phase diagrams show corresponding state behaviour. In accordance with the prediction of the restricted primitive model (RPM), which is a model fluid of equal sized, charged hard spheres in a dielectric continuum, the critical points are located at low temperature and low concentration, when the corresponding state variables of this model are used. However, the critical temperature Tc* and the critical density ρc* are well below the figures of the RPM prediction. Comparison is made with the phase diagrams of alcohol solutions of imidazolium ionic liquids and with simulation results of the RPM.