Tetrahedral Liquid-Crystalline Networks: An A15-Like Frank-Kasper Phase Based on Rod-Packing

Angew Chem Int Ed Engl. 2022 Jul 4;61(27):e202203447. doi: 10.1002/anie.202203447. Epub 2022 May 13.

Abstract

The Pm 3 n cubic and other low-symmetry Frank-Kasper phases are known to be formed by soft spheres, ranging from metals to block copolymer micelles and colloidal nanoparticles. Here, we report a series of X-shaped polyphiles composed of sticky rods and two non-symmetric branched side-chains, which self-assemble into the first example of a cubic liquid-crystalline phase representing a tetrahedral network of rods with a Pm 3 n lattice. It is the topological dual to the Weaire-Phelan foam, being the Voronoi tessellation of the A15 sphere packing, from which this network is obtained by Delaunay triangulation.

Keywords: Cubic Liquid Crystals; Delaunay Triangulation; Frank-Kasper Phases; Self-Assembly; Tetrahedral Networks.