Stacking and Elasticity of Ionic Chromonic Liquid Crystals

Lyotropic chromonic liquid crystals (chromonics) exhibit a unique self-assembly process of theoretical and practical interest, whose characteristic feature is molecular association through stacking at extremely low concentrations. Experimental evidence has suggested that this process is approximately isodesmic across a broad concentration range. Interestingly, these materials also exhibit a strong elastic anisotropy that leads to novel phases in confinement, where imposed deformations exploit an elastically cheap mode. Here, we present a minimal model intended to capture key features of the lyotropic chromonic phase. The model is utilized to interrogate the role of energetic anisotropies, to identify their effects on particle stacking and molecular ordering, and subsequently examine the role of stacking and stack structure in producing the large elastic anisotropies of these materials.