Microscopic, Mesoscopic and Macroscopic Supramolecular Assembly in Extraction Specific Functions of Ionic Liquids

In liquid-liquid extraction systems, extractants and extracted complexes may have surface activity, resulting in the formation of a variety of supramolecular assemblies such as vesicles and micelles. The assemblies are limited at microscopic and mesoscopic scales. Researches on interface of extraction also focus on microscopic and mesoscopic scales at present. Recently, our group first reported macroscopic supramolecular assembly(MSA) at the interface of extraction systems. The interface can be studied on macroscopic scales by MSA. The process of MSA in ionic liquids(ILs) based extraction systems also provides a new way to study complex supramolecular interactions between ILs and mediums. This review focused on microscopic, mesoscopic and macroscopic supramolecular assembly in extraction systems. First, the interface properties and the process of ion exchange in extraction were summarized. Next, the structures of mesoscopic supramolecular assemblies were reviewed . Finally, the macroscopic supramolecular assembly(MSA) at the interface of extraction systems and its application on separation were emphatically introduced. The MSA process at the interface enriches the extraction methods. And the Marangoni effect presented at the interface supplies a new approach to provide continuous driving force, which is an important scientific problem in the field of MSA.