Aqueous micellar two-phase systems (AMTPS) hold a large potential for cloud point extraction of biomolecules but are yet poorly studied and characterized, with few phase diagrams reported for these systems, hence limiting their use in extraction processes. This work reports a systematic investigation of the effect of different surface-active ionic liquids (SAILs)—covering a wide range of molecular properties—upon the clouding behavior of three nonionic Tergitol surfactants. Two different effects of the SAILs on the cloud points and mixed micelle size have been observed: ILs with a more hydrophilic character and lower critical packing parameter (CPP < ¹/₂) lead to the formation of smaller micelles and concomitantly increase the cloud points; in contrast, ILs with a more hydrophobic character and higher CPP (CPP ≥ 1) induce significant micellar growth and a decrease in the cloud points. The latter effect is particularly interesting and unusual for it was accepted that cloud point reduction is only induced by inorganic salts. The effects of nonionic surfactant concentration, SAIL concentration, pH, and micelle ζ potential are also studied and rationalized.

中文翻译：

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表面活性离子液体对非离子表面活性剂浊点的影响及胶束水两相体系的形成

水胶束两相系统（AMTPS）在生物分子的浊点萃取方面具有很大潜力，但尚未得到充分研究和表征，这些系统的相图报道很少，因此限制了它们在萃取过程中的使用。这项工作报告了对三种表面活性离子液体（SAIL）对三种非离子Tergitol表面活性剂的混浊行为的影响-涵盖了广泛的分子特性-进行了系统的研究。已经观察到在浊点和混合胶束大小帆的两种不同的效果：离子液体与更亲水的性质和降低临界填充参数（CPP < ¹ / ₂）导致形成较小的胶束并随之增加浊点；相反，具有更疏水特性和更高CPP（CPP≥1）的IL诱导明显的胶束生长和浊点降低。后一种效果特别有趣且不寻常，因为公认浊点降低仅由无机盐引起。还研究并合理化了非离子表面活性剂浓度，SAIL浓度，pH和胶束ζ电势的影响。