On the Miscibility of Nematic Liquid Crystals with Ionic Liquids and Joint Reaction for High Helical Twisting Power Product(s)

Mixtures of nematic liquid crystals (LCs) with chiral ionic liquids (CILs) may find application as active materials for electrically driven broadband mirrors. Five nematic liquid crystal hosts were mixed with twenty three ionic liquids, including chiral ones, and studied in terms of their miscibility within the nematic phase. Phase diagrams of the mixtures with CILs which exhibited twisted nematic phase were determined. Miscibility, at levels between 2 and 5 wt%, was found in six mixtures with cyanobiphenyl-based liquid crystal host—E7. On the other hand, the highest changes in the isotropization temperature was found in the mixtures with isothiocyanate-based liquid crystal host—1825. Occurrence of chemical reactions was found. A novel chiral binaphtyl-based organic salt [N11116][BNDP] was synthesized and, in reaction to the 1825 host, resulted in high helical twisting power product(s). Selectivity of the reaction with the isothiocyanate-based liquid crystal was found.

Effect of the degree of protonation of amino acid dopants in Chirality amplification in DSCG Lyotropic Nematic phases.

Disodium Cromoglycate (DSCG), a lyotropic liquid crystal in water, is shown to be an amplifier of chirality when doped with small chiral molecules. Here, we study the behaviour of the DSCG nematic phase in the presence of three aminoacids with different degrees of protonation: L-Alanine, L-Arginine·HCl and L-Arginine. The results demonstrate that the sign of the helicity of the doped nematic phase (i.e., a cholesteric phase) depends on the sign of the Helical Twisting Power of the dopant.

Chirality enhancement in macro-chiral liquid crystal nanoparticles

Chirality amplification in mesomorphic gold nanoparticles (NPs) functionalized with chiral ligands and liquid crystal (LC) groups in LC matrices is detected. Attaching LC groups to NPs leads to a significant increase of the helical twisting power.

Relationship between molecular structures of uniquely designed C2-symmetric axially chiral dopants and their helical twisting properties in cholesteric liquid crystals

9,9′-biphenanthrene-type chiral dopants were newly synthesized for the development of functional liquid crystal (LC) materials with enhanced properties. A cholesteric LC (CLC) with a chiral dopant showed positive temperature dependence of helical twisting power and a CLC with temperature independence was developed by mixing two types of chiral dopants.