Helical twisting power and compatibility in twisted nematic phase of new chiral liquid crystalline dopants with various liquid crystalline matrices

0511155 - FZÚ 2020 RIV GB eng J - Journal Article
Duda, Ł. - Czajkowski, M. - Potaniec, B. - Vaňkátová, Petra
Helical twisting power and compatibility in twisted nematic phase of new chiral liquid crystalline dopants with various liquid crystalline matrices.
Liquid Crystals. Roč. 46, č. 12 (2019), s. 1769-1779. ISSN 0267-8292. E-ISSN 1366-5855
R&D Projects: GA ČR GA19-03564S
Institutional support: RVO:68378271
Keywords : chiral dopants * helical twisting power * phase diagrams * twisted nematic phase * hydrogen bonds * blue phase
OECD category: Organic chemistry
Impact factor: 2.908, year: 2019
Method of publishing: Limited access
https://doi.org/10.1080/02678292.2019.1599454

Chiral dopants exhibiting smectic phases were prepared and their helical twisting power (HTP) and thermal phase behaviour in mixtures with LC hosts were studied. The influence of host LC on HTP was evaluated and generally higher values were found for hosts with high birefringence. High enhancement was found for LC-chiral dopant pair both having similar aromatic core. Chiral dopants exhibited limited compatibility with LC hosts in twisted nematic phase at room temperature. For one mixture, single twisted nematic phase with selective light reflection band with maximum at wavelength about 1.0 µm was obtained. Carboxylic acid dopants exhibited total compatibility with the host in single twisted nematic phase at elevated temperatures, allowing preparation of mixtures with reflection band in the visible range, blue phases were observed, too. Intermolecular hydrogen bonding between acid proton and pyridine nitrogen of dopants was found.
Permanent Link: http://hdl.handle.net/11104/0301489