(352c) The Effect of Flow on Frustrated Polymer-Stabilized Blue Phase Liquid Crystals

In blue phase liquid crystals, molecules self-organize into double twisted cylinders (DTC). The energetically favorable DTC structures self-assemble into three-dimensional cubic lattice structures that can reflect the light in the range of the visible wavelength. The double twisted cylinders are, however, unable to occupy the entire 3D volume of the lattice structures, which leads to the formation of disclination lines. The high energy of the disclination lines limits the stability of the blue phases to a narrow range of temperatures. The judicious approach that has been implemented to stabilize these structures is embedding reactive materials such as polymers or nanoparticles in the high energy regions. Among different stabilization approaches, using polymers has been successful in expanding the stability range of the blue phases to several tens of degrees Celsius. Due to their fluid-like structures, the blue phase liquid crystals are able to conform to different topological constraints. Recent computational studies have shown that confining the blue phase liquid crystals into minuscule geometries can also lead to the expansion of thermal stability regions as well as the advent of novel configurations. In this research work, we explore the behavior of polymer-stabilized blue phase liquid crystals within spherical micro-confinement. We study the effect of confinement by controlling the size of the droplets using a capillary microfluidic device. Our results show that polymerizing the blue phases within the droplets with flow deformation memory results in new exotic structures. Moreover, the transition temperature of the blue phases in the polymerized droplets become strongly size correlated.