Gemini supra-amphiphiles with finely-controlled self-assemblies.

Abstract

Novel gemini supra-amphiphiles, [Mim-4-Mim][DBS](2) and [Mim-4-Mim][DS](2), were facilely constructed. A slight variation of building blocks can effectively modulate the driving forces for the fabrication of gemini supra-amphiphiles, thus leading to the fine control of subsequent self-assemblies. [Mim-4-Mim][DS](2), constructed via electrostatic attraction, tends to form micelles and hexagonal liquid crystals. Rich lamellar structures, including unilamellar and multilamellar vesicles, planar bilayers, and lamellar liquid crystals can be formed by [Mim-4-Mim][DBS](2), which is constructed through electrostatic and π-π stacking interactions. With increasing temperatures, [Mim-4-Mim][DBS](2) exhibits interesting phase separation in the L(a) phase, behaving like common nonionic surfactants. The cross-linking between vesicles, where the "bola-type" [Mim-4-Mim](2+) cations act as the bridges, was found to promote the elongation of aggregates until the occurrence of phase separation.