The Cholesteric-Nematic Transition in Thin Layers of Nematic-Cholesteric Mixtures

• Published in: Molecular Crystals and Liquid Crystals Vol. 534; no. 1; pp. 32 - 40
• Main Authors: Hotra, Z., Mykytyuk, Z., Hotra, O., Fechan, A., Syshynskyy, O., Yasynovska, O., Kotsun, V.
• Format: Journal Article
• Language: English
• Published: Philadelphia Taylor & Francis Group 01-01-2011; Taylor & Francis Ltd
• Subjects: Cholesteric-nematic transition; Crystals; Deformation; Dopants; focal-conic deformation; liquid crystal mixtures; Liquid crystal polymers; Liquid crystals; Nematic; Optical activity; Phase transitions; Semiconductor doping; Thin films; Threshold voltage
• ISSN: 1542-1406; 1563-5287; 1527-1943
• DOI: 10.1080/15421406.2010.526565

In this article the investigation of the cholesteric-nematic transition in thin layers of nematic-cholesteric mixtures is carried out. Nematic-cholesteric mixtures based on a nematic matrix MLC-1 with a low concentration (up to 2%) of an optically active dopant were the object of this investigation. The dependencies of threshold voltages of focal-conic deformation and forward cholesteric-nematic transition for different thicknesses of a liquid-crystal layer are obtained. It was demonstrated that the twist effect in induced cholesterics can be considered as a simple case of a cholesteric-nematic effect in thin liquid-crystal layers.