Curvature-induced configuration transition in confined nematic liquid crystals

Stable nematic director fields of liquid crystals confined to cylindrical cavities which enforce homogeneous concentric anchoring depend on the competition between azimuthal and polar molecular anchoring strengths and the surface elastic constant ${\mathit{K}}_{24}$. Deuterium nuclear-magnetic-resonance line shapes of such systems reveal a structural transition from an escaped-twisted to a newly discovered planar-bipolar configuration as the curvature is varied. This observation allows for the first determination of the polar and azimuthal anchoring energies and ${\mathit{K}}_{24}$, by a single experimental method.