Effect of Central Longitudinal Dipole Interactions on Chiral Liquid-Crystal Phases

Int J Mol Sci. 2018 Sep 11;19(9):2715. doi: 10.3390/ijms19092715.

Abstract

Monte Carlo simulations of chiral liquid-crystals, represented by a simple coarse-grained chiral Gay⁻Berne model, were performed to investigate the effect of central longitudinal dipole interactions on phase behavior. A systematic analysis of the structural properties and phase behavior of both achiral and chiral systems, with dipole interactions, reveals differing effects; strong dipole interactions enhance the formation of layered structures; however, chiral interactions may prevent the formation of such phases under certain conditions. We also observed a short-ranged smectic structure within the cholesteric phases with strong dipole interactions. This constitutes possible evidence of presmectic ordering and/or the existence of chiral line liquid phases, which have previously been observed in X-ray experiments to occur between the smectic twisted grain boundary and cholesteric phases. These results provide a systematic understanding of how the phase behavior of chiral liquid-crystals changes when alterations are made to the strength of dipole interactions.

Keywords: chirality; dipole; liquid crystals; molecular simulation; phase transition.

MeSH terms

  • Liquid Crystals / chemistry*
  • Models, Chemical
  • Molecular Dynamics Simulation
  • Monte Carlo Method
  • Phase Transition
  • Static Electricity
  • Stereoisomerism