Abstract In this work, the use of ionic liquids as phase-forming components of Aqueous Two-Phase Systems (ATPS) has been evaluated. All ionic liquids used are based on the imidazolium cation, with different alkyl side chains and anions (chloride, bromide, acetate or dicyanamide). As counterpart on the ATPS, a random co-polymer of ethylene oxide and propylene oxide monomers (named EOPO or UCON) was used. Phase diagrams (tie-lines and binodal curves) for a set of UCON/ionic liquid ATPS were measured experimentally at T = (288.15, 298.15 and 308.15 K), using the density and refractive index of the mixtures to obtain the composition of equilibrium phases. The extension of the heterogeneous region increases but the slope of the tie-lines did not change significantly with temperature. Anions had a dramatic effect on the ATPS immiscibility, where acetate produced the largest heterogeneous region and thiocyanate the smallest, following the series OAc− > Cl− > Br− > SCN−. The Chen-NRTL and modified Wilson models were used to correlate the liquid–liquid equilibrium data, but better results were obtained with the Chen-NRTL model.

中文翻译：

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聚合物/离子液体水性两相体系的相平衡

摘要 在这项工作中，评估了使用离子液体作为水性两相系统 (ATPS) 的相形成组分。所使用的所有离子液体均基于咪唑鎓阳离子，具有不同的烷基侧链和阴离子（氯化物、溴化物、醋酸盐或双氰胺）。作为 ATPS 上的对应物，使用了环氧乙烷和环氧丙烷单体（命名为 EOPO 或 UCON）的无规共聚物。在 T = (288.15、298.15 和 308.15 K) 下，通过实验测量了一组 UCON/离子液体 ATPS 的相图（连接线和双节点曲线），使用混合物的密度和折射率来获得平衡相的组成. 非均质区域的延伸增加，但连接线的斜率不随温度显着变化。阴离子对 ATPS 不混溶性有显着影响，其中醋酸盐产生最大的异质区域，硫氰酸盐最小，遵循系列OAc-> Cl-> Br-> SCN-。Chen-NRTL 和修正的 Wilson 模型用于关联液-液平衡数据，但使用 Chen-NRTL 模型获得了更好的结果。