Multiscale Simulation of Flow-Induced Texture Formation in Thermotropic Liquid Crystals
D. Grecov and A.D. Rey
McGill University, CA
Keywords: liquid crystal polymers, textural transformations, inversion walls, defects
This paper presents theory and simulation of flow-induced structures, useful to the creation of synthetic material structures and to the biomimetics of natural fibers. We present a multiscale theory and simulation of hydrodynamic texture formation to provide fundamental principles for control and optimization of structures in liquid crystal polymers. In thermotropic flow-aligning nematic polymers it found that as the shear-rate increases, the pathway between an oriented non-planar state and an oriented planar state is through texture formation and coarsening, temperature and shear rate being efficient fields to control the grain size of the texture. High temperatures and shear rates lead to defect free monodomains. The texture transition cascade: unoriented monodomain - defect lattice - defect gas - oriented monodomain is remarkably consistent with the experimentally observed textural transitions of sheared lyotropic nematic polymers.
Nanotech 2004 Conference Technical Program Abstract