Department of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn Straße 6, 44227, Dortmund, Germany.
Center of Molecular Spectroscopy and Simulation of Solvent-driven Processes (ZEMOS), Ruhr-University Bochum, 44801, Bochum, Germany.
Chemistry. 2022 Feb 24;28(12):e202104228. doi: 10.1002/chem.202104228. Epub 2022 Feb 3.
Nonaqueous emulsions are crucial for a range of applications based on water-sensitive systems such as controlled polymerizations requiring anhydrous reaction conditions and the stabilization of readily hydrolyzable reagents or pharmacologically active components. However, defined molecular surfactants to stabilize such nonaqueous emulsions are scarce. We introduce a self-assembled coordination cage, decorated with cholesterol functionalities, to serve as a molecular surfactant for various oil-in-oil emulsions of immiscible organic solvents. While the positively charged cage forms the amphiphile's polar moiety, the non-polar cholesterol appendices can bend in a common direction to stabilize the emulsion. Templated by the droplets, polycondensation reactions were carried out to produce microstructured polyurethane and polyurea materials of different particle sizes and morphologies. Further, the amphiphilic cage can encapsulate a guest molecule and the resulting host-guest assembly was also examined as a surfactant. In addition, the aggregation behavior of the amphiphilic cage in an aqueous medium was examined.
非水乳液对于一系列基于对水敏感的系统的应用至关重要，例如需要无水反应条件的可控聚合以及易水解试剂或药理活性成分的稳定。然而，用于稳定这种非水乳液的定义明确的分子表面活性剂却很少。我们引入了一种自组装的配位笼，用胆固醇官能团进行修饰，用作各种不混溶有机溶剂的油包油乳液的分子表面活性剂。虽然带正电荷的笼形成两亲体的极性部分，但非极性胆固醇侧链可以朝共同的方向弯曲以稳定乳液。在液滴的模板作用下，进行缩聚反应，以产生具有不同粒径和形态的微结构化聚氨酯和聚脲材料。此外，两亲性笼可以包封客体分子，并且还研究了所得的主客体组装作为表面活性剂。另外，还研究了两亲性笼在水介质中的聚集行为。
