Abstract

A delicate balance of noncovalent interactions drives hydrated molecular amphiphiles to self-assemble into lyotropic liquid crystals (LLCs) of varied topologies, the exquisite nanodomain structures of which suggest applications as separations membranes, mesoporous materials synthesis templates, and therapeutic delivery vehicles. Based on hard sphere colloidal crystals, spherical micelles are intuitively expected to form high symmetry face-centered cubic (FCC) and hexagonally close-packed (HCP) LLCs. However, we recently discovered that ionic surfactant micelles also form a zoo of low symmetry, tetrahedrally close-packed Frank-Kasper (FK) phases that mimic the structures of elemental metals and their alloys. The emergence of complex FK s, A15, C14, and C15 LLCs arises from a frustrated non-covalent force balance that minimizes local variations in amphiphile solvation, while maximizing electrostatic cohesion in the ionic micelle ensemble. We describe how chemical features of the amphiphiles and the path-dependent processing of their aqueous dispersions drive LLC sphere packing symmetry selection, culminating in our discovery of the ability of oil-swollen ionic micelles to aperiodically order into lyotropic dodecagonal quasicrystals (DDQCs). Thus, engineering molecular frustration into simple amphiphiles begets high fidelity, (a)periodic pattern formation at length scales far exceeding those of their constituent molecular and supramolecular building blocks.