Orientational structures in cholesteric droplets with homeotropic surface anchoring

Krakhalev, Mikhail N.; Rudyak, Vladimir Yu.; Prishchepa, Oxana O.; Gardymova, Anna P.; Emelyanenko, Alexander V.; Liu, Jui-Hsiang; Zyryanov, Victor Ya. Source: SOFT MATTER, 15 (28):5554-5561; 10.1039/c9sm00384c JUL 28 2019

The dependency of orientational structures in cholesteric droplets with homeotropic surface anchoring on the helicity parameter has been studied by experiment and simulations. We have observed a sequence of structures, in which the director configurations and topological defects were identified by comparison of polarized microscopy pictures with simulated textures. A toron-like and low-symmetry intermediate layer-like structures have been revealed and studied in detail. The ranges of stability of the observed structures have been summarized in a general diagram and explained by the helicity parameter dependence of the free energy terms.