Winding up dynamics for matched and unmatched elastic constants in chiral nematic liquid crystals†

Abstract

Recently discovered materials have opened up the possibility of easily and repeatably altering the ratio among the elastic constants characterizing nematic liquid crystals. These ratios are crucial for defining the pathways for the relaxation process from the unwound state to the Grandjean (planar) state in chiral nematics. In this study, we use the Landau–de Gennes method in the Q-tensor formalism to investigate this textural transition for different bend-to-twist ratios representing nematic phases that are currently easily prepared. We also examine the effect of varying alignment conditions and strength on this transition and make qualitative comparisons with experimental data. This work demonstrates how the dynamics are entirely different under small changes in the material and the confinement and how one can use its results to design reflective chiral nematic displays.