Emergence of Smectic Mesophase in Binary Mixtures of Pure Nematogens

TLDR: In this article, a binary system consisting of (A) p-nitrophenyl-p'-n-amyloxycinnamate (90.5-120.5°) and (B) pmethoxyphenyl -p-n-heptyl-methynyl -n-oxidecinnamide (91.0-120°) is presented, which transforms the original nematic texture into a mixed smectic A texture over a range of temperature and concentration.

Abstract: Binary mixtures both components of which are liquid crystals are known to form continuous mixed liquid crystals.1 Most of them do not undergo any change in their mesomorphic textures, though a few have been found to give rise to different textures.2 We report here a binary system consisting of (A) p-nitrophenyl-p'-n-amyloxycinnamate (90.5–120.5°) and (B) p-methoxyphenyl-p'-n-heptyloxycinnamate (91.0–120.5°) which transforms the original nematic texture into a mixed smectic A texture over a range of temperature and concentration. Both components individually are nematic liquid crystals. In their binary mixtures, a two dimensional more ordered mixed Smectic A mesophase emerges between 5.0–92.5 mol% of p-methoxyphenyl-p'-n-heptyloxycinnamate over a temperature range of about 50–105° at its maximum. The mixed smectic-nematic transition curve shows a marked rounded concavity, extrapolation of which on either side yields values of latent transition temperatures 77.0° and 66.5° for the components A and ...