Aqueous dispersions of nanostructures formed through the self-assembly of iminolipids with exchangeable hydrophobic termini

作者：Li Wen; McManus Daryl; Liu Han; Casiraghi Cinzia; Webb Simon J^*

来源：Physical Chemistry Chemical Physics, 2017, 19(26): 17036-17043.

DOI：10.1039/c7cp02868g

The addition of amines to an aldehyde surfactant, which was designed to be analogous to didodecyldimethylammonium bromide, gave exchangeable ''iminolipids'' that self-assembled to give stable aqueous dispersions of nano-sized vesicles. For example, sonication of suspensions of the n-hexylamine-derived iminolipid gave vesicles 50 to 200 nm in diameter that could encapsulate a water-soluble dye. The iminolipids could undergo dynamic exchange with added amines, and the resulting equilibrium constants (K-rel) were quantified by H-1 NMR spectroscopy. In the absence of lipid self-assembly, in CDCl3, the assayed primary amines gave very similar K-rel values. However in D2O the value of Krel generally increased with increasing amine hydrophobicity, consistent with partitioning into a self-assembled bilayer. Amines with aromatic groups showed significantly higher values of K-rel in D2O compared to similarly hydrophobic alkylamines, suggesting that pi-pi interactions favor lipid self-assembly. Given this synergistic relationship, pi-rich pyrenyliminolipids were created and used to exfoliate graphite, leading to aqueous dispersions of graphene flakes that were stable over several months.

• 出版日期2017-7-14