Determination of the temperature dependence of the helical pitch in 1.m.7(HH) liquid crystalline compounds
Journal Title: Bulletin of the Military University of Technology - Year 2018, Vol 67, Issue 2
Abstract
Homologous series 1.m.7(HH) of liquid crystalline compounds, varying in the chiral chain length m (m=4-9), were studied. These compounds are characterized by a long helical pitch in an antiferroelectric phase, which is higher than the measuring range of the available instruments. The temperature dependence of the helical pitch of these compounds was determined by the extrapolation of the results obtained for the mixtures of 1.m.7(HH) compounds with 1.4.7(HF) compound of a known helical pitch value. The helical pitch measurements were made by spectrophotometry and phase transition temperatures were measured by polarizing thermomicroscopy. Extrapolation of the results let established that the investigated liquid crystals are characterized by the helical pitch increasing and then decreasing upon heating, which is accompanied by the helical twist sense inversion from the right-handed structure to the left-handed one. Keywords: liquid crystals, antiferroelectric phase, helical pitch, miscibility study<br/><br/>
Authors and Affiliations
Paulina Zieja, Marzena Tykarska, Katarzyna Strójwąs
Keywords
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- EP ID EP346547
- DOI 10.5604/01.3001.0012.0953
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