Self-assembly of liquid crystalline nanostructures in aqueous solution
Seminar Room 1, Newton Institute
AbstractChromonic mesogens are non-conventional amphiphiles, which self-assemble in aqueous solution to form aggregate structures: rods, stacks or layers. At higher concentrations these aggregates can self-organise to form chromonic mesophases. Initial self-assembly is different to that seen in most conventional amphiphiles: it is enthalpically-driven and takes place in the absence of a critical micelle concentration. Subsequent mesophase formation is driven by entropic factors.
There is great interest in chromonic systems as materials for the fabrication of new thin films for biosensors and optical compensators; and also because a better fundamental understanding of chromonic self-assembly is required to control aggregate structure formation in certain classes of drug molecules.
This talk presents results from molecular simulation studies of chromonic self-assembly at different levels of detail. Atomistic molecular dynamics simulations of the dye molecule, sunset yellow, and the drug molecule, disodium cromoglycate, determine for the first time the structure and dynamical properties of chromonic aggregates in aqueous solution. Showing how subtle changes in intermolecular interactions can change the mode of self-assembly. Coarse-grained models, at the level of dissipative particle dynamics (DPD), demonstrate how simulation provides a tool to engineer new nanostructures by exploring the role of molecular shape and interactions in determining the structure of aggregates formed.