Quaternized cyclodextrin (CD) obtained by quaternization reaction of bromine-CD and , -Dimethylethylenediamine, are used for preparing PV membranes. Three different kinds of composite membranes are interfacially synthesized on the polyacrylonitrile substrate. The different sequences of piperazine and quaternized CD reacted with trimesoyl trichloride show a great difference in separation of polar/nonpolar mixture. The topmost layer of CD-based polyamide layer shows a higher separation factor, which can be inferred that quaternized CD played the major role during separation. Quaternized CD can integrate cavity size, polar and non-polar characteristics to achieve exceptional screening performance. PV performance of the optimal membrane at 25 °C is measured using the 5 wt% ethanol and cyclohexane mixture, exhibiting the separation factor of 66.7. PV performances of other different organic mixtures prove that nonpolar inner cavity of CD has a stronger inclusion of cyclohexane than other smaller nonpolar molecules, thus enhancing the repulsion of cyclohexane from the mixture. In summary, these outside polar quaternary ammonium salt structures of quaternized CD have a high selectivity for polar solvents. The nonpolar cavity of CD shows the inclusion ability of nonpolar solvents, especially the organic solvent with large molecular volume, which hinders their penetration and improves the separation factor.

中文翻译：

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用于通过渗透蒸发过程分离和纯化乙醇/环己烷混合物的多功能分离层

溴-CD与，-二甲基乙二胺季铵化反应得到季铵化环糊精(CD)，用于制备PV膜。在聚丙烯腈基材上界面合成了三种不同类型的复合膜。哌嗪和季铵化CD与均苯三甲酰三氯反应的不同顺序在极性/非极性混合物的分离中表现出很大的差异。最顶层的CD基聚酰胺层显示出较高的分离因子，这可以推断季铵化的CD在分离过程中起主要作用。季铵化 CD 可以整合腔体尺寸、极性和非极性特性，以实现卓越的筛选性能。使用 5 wt% 乙醇和环己烷混合物测量了 25 °C 时最佳膜的 PV 性能，显示分离系数为 66.7。其他不同有机混合物的PV性能证明，CD的非极性内腔比其他较小的非极性分子对环己烷的包容性更强，从而增强了混合物中环己烷的排斥力。综上所述，季铵化CD的这些外部极性季铵盐结构对极性溶剂具有高选择性。 CD的非极性空腔表现出非极性溶剂，特别是分子体积大的有机溶剂的包合能力，阻碍其渗透，提高分离因子。