Self-assembly and mesophase formation in a non-ionic chromonic liquid crystal system: insights from dissipative particle dynamics simulations

Results are presented from a dissipative particle dynamics (DPD) simulation of a model non-ionic chromonic system, TP6EO2M, composed of a poly(ethylene glycol) functionalised aromatic (triphenylene) core. The simulations demonstrate self-assembly of chromonic molecules to form single molecule stacks in solution at low concentrations, the formation of a nematic mesophase at higher concentrations and a columnar phase in the more concentrated regime. The simulation model used allows very large system sizes, of many thousands of particles, to be studied. This provides, for the first time, an opportunity to study chromonic phase behaviour by simulation without severe restrictions imposed by system size. In the low concentration limit, the simulations demonstrate approximate isodesmic association from which a binding energy can be obtained, allowing the simulations to be tuned to reproduce the behaviour of the real experimental system.