Virgil Percec
Molecular Physics: https://doi.org/10.1080/00268976.2021.1902586
Frank-Kasper phases are available in both hard and soft complex matter. They have been discovered in metal alloys and subsequently in self-organisations of supramolecular spheres from self-assembling dendrons, dendrimers and dendronized polymers. Recently, they were found in block copolymers, lipids, surfactants, giant surfactants, nanoparticles, DNA particles and even in condensed small molecules such as N2, O2, and CO. Here we report the discovery of an amphiphilic Janus dendrimer, that self-assembles in water into vesicles known as dendrimersomes, self-organised also in bulk state into helical columns and spheres forming columnar hexagonal and a Frank-Kasper A15 phase known as Pm3¯3¯n. These self-organisations display a supramolecular orientational memory (SOM) effect that is induced by an epitaxial nucleation at the transition from columns to spheres and during the reverse process. This SOM effect is mediated by the closed contact supramolecular spheres from the A15 phase. In this case a rhombitruncated cuboctahedral hexagonal columnar arrangement, that to the best of our knowledge is not known in biology or synthetic chemistry, was self-organised. We believe that the addition of amphiphilic Janus dendrimers to the classes of molecules displaying Frank-Kasper phases and the SOM effect will broaden our ability to discover additional complex soft condensed matter morphologies.