Switching dynamics in cholesteric liquid crystal emulsions
arXiv:1707.09949 · doi:10.1063/1.4997637
Abstract
In this work we numerically study the switching dynamics of a 2D cholesteric emulsion droplet immersed in an isotropic fluid under an electric field, which is either uniform or rotating with constant speed. The overall dynamics depend strongly on the magnitude and on the direction (with respect to the cholesteric axis) of the applied field, on the anchoring of the director at the droplet surface and on the elasticity. If the surface anchoring is homeotropic and a uniform field is parallel to the cholesteric axis, the director undergoes deep elastic deformations and the droplet typically gets stuck into metastable states which are rich in topological defects. When the surface anchoring is tangential, the effects due to the electric field are overall less dramatic, as a small number of topological defects form at equilibrium. The application of the field perpendicular to the cholesteric axis usually has negligible effects on the defect dynamics. The presence of a rotating electric field of varying frequency fosters the rotation of the defects and of the droplet as well, typically at lower speed than that of the field, due to the inertia of the liquid crystal. If the surface anchoring is homeotropic a periodic motion is found. Our results represent a first step to understand the dynamical response of a cholesteric droplet under an electric field and its possible application in designing novel liquid crystal-based devices.
39 pages
References in corpus (17)
- Theory of Phase Ordering Kinetics
- Steady-state hydrodynamic instabilities of active liquid crystals: Hybrid lattice Boltzmann simulations
- Lattice Boltzmann Simulations of Liquid Crystal Hydrodynamics
- Hydrodynamics of topological defects in nematic liquid crystals
- A minimal physical model captures the shapes of crawling cells
- Simulations of liquid crystal hydrodynamics
- Phase separating binary fluids under oscillatory shear
- Hybrid lattice Boltzmann model for binary fluid mixtures
- Self-assembly of colloid-cholesteric composites provides a possible route to switchable optical materials
- Numerical calculations of the phase diagram of cubic blue phases in cholesteric liquid crystals
- Permeative flows in cholesteric liquid crystals
- Continuous rotation of achiral nematic liquid crystal droplets driven by heat flux
- Colloidal templating at a cholesteric - oil interface: Assembly guided by an array of disclination lines
- Thermodynamics of Blue Phases In Electric Fields
- Bistable defect structures in blue phase devices
- Switching and defect dynamics in multistable liquid crystal devices
- Shear dynamics of an inverted nematic emulsion