Chirality plays a crucial role in condensed and biological matter. However, understanding how chiral symmetry breaking on the molecular scale alters the physical behavior of materials remains a challenging topic. We have studied chiral nematic fluids of helicoidal patchy cylinders as a generic model for chiral biopolymers and helix-shaped colloids. Using microscopic theory and computer simulation we find that the handedness of the chiral nematic fluid may spontaneously flip sign upon changing the system density or temperature while preserving the chiral features of the individual particles. We show that these inversions are generic and can be expected in cholesteric phases of both thermotropic and lyotropic origin. The mechanism underpinning the symmetry inversions can be explained in terms of an antagonistic effective torque acting between helical rods. In a second model we take a closer look at steric chirality of weakly curled hard rods in order to assess the impact of short versus long-ranged chiral forces on the mesostructure. Time permitting I will finish by briefly discussing the role of director fluctuations near the inversion point and demonstrate the impact of geometric confinement to describe twist propagation in twisted smectic membranes.

Connecting micro- and mesoscale chirality in nematic fluids: Insights from simple models

256th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.