Oblique helicoidal state of the twist-bend nematic doped by chiral azo-compound

Beyond Color Boundaries: Pioneering Developments in Cholesteric Liquid Crystal Photonic Actuators

“… Oblique helicoidal cholesteric liquid crystals and electrically tunable structural colors. ( a ) Comparison diagram between CLC spiral nanostructures and oblique helicoidal CLC nanostructures [ 123 ]. ( b ) OHCLCs selectively shift their reflection wavelength towards a longer wavelength range under a reduced electric field [ 123 ].…”

“…( a ) Comparison diagram between CLC spiral nanostructures and oblique helicoidal CLC nanostructures [ 123 ]. ( b ) OHCLCs selectively shift their reflection wavelength towards a longer wavelength range under a reduced electric field [ 123 ]. ( c ) Electric field controlled selective reflection of light in DCM-doped CLC mixture, photos under ambient light conditions and corresponding polarized optical microscopy photos of DCM sample pool [ 124 ].…”

“…Under ultraviolet light, the cis–trans isomerization of photoactive compounds leads to a red shift in selective light reflection in cholesterol mixtures. Vitalli Chornous et al induced helical distortion of the mixture of CB7CB/CB6OCB using the novel photosensitive chiral dopant ChD-3816 (an azo compound containing 4-hexyloxyphenyl and 2-isopropyl-5-methylcyclohexylbenzoate), and they added 5CB to reduce the phase transition temperature of the oblique helicoidal state of a twist–bend nematic doped with a chiral azo-compound [ 123 ]. Through experiments, they found that the CLC mixture can form OHCLCs under an AC electric field at temperatures higher than the phase transition.…”