A case of mistaken identity: spontaneous formation of twisted bipolar droplets from achiral nematic materials

Abstract

New observations of the structure of nematic droplets containing material with a low K33/K11 ratio indicate that these droplets adopt a twisted bipolar, rather than concentric, orientation. The data supporting this new interpretation are presented and discussed. These data provide verification for a prediction of Williams regarding the relative stabilities of bipolar, twisted bipolar, and concentric droplets. Nematic liquid crystals confined to spheres and cylinders form a general class of structures in which achiral molecules can form chiral structures due to the combination of external boundary conditions and the minimization of the free energy near defect structures.