A Twist on Self-Assembly: Hierarchical Architectures Formed by Amphiphilic Chromonics

Amphiphilic molecules have been harnessed by biology and engineering alike for their propensity to self-assemble into complex structures. In this, steric molecular-scale interactions dominate small aggregates, whilst emergent elasticity governs as objects grow to larger length-scales. Here, we use molecular dynamics simulation of a series of coarse-grained mesogenic systems to examine the self-assembly of such supramolecular structures. The simulated systems, which are bipartite mixtures of disc-shaped and spherical particles, combine the thread-like aggregation of chromonics with the frustrations and incommensurabilities of amphiphilicity.

A veritable zoo of structures, many of which possess emergent supramolecular chirality, are reproducibly obtained. These including double helices, twisted bilayers, multi-strand ropes and tubules. By assessing the sensitivity of these final structures to the underpinning particle-scale interactions, insight is gained into how emergent length-scales can develop in grown structures. Further, from time-lines of the associated hierarchical self-assembly processes, the importance of mesogenic intermediates and size-dependent morphological changes in the development of complex aggregates is evidenced.