Molecularly Designed Chromonic Liquid Crystals for the Fabrication of Broad Spectrum Polarizing Materials

Abstract

The chromonic mesogens shown were designed to absorb at different wavelengths and yet display chromonic liquid-crystalline properties in a common solvent. Induced orientation of the mixed liquid crystals by a mechanical shearing force followed by evaporation of solvent produced anisotropic solid films that polarize light from about 450 to 890 nm.

Shear-induced polydomain structures of nematic lyotropic chromonic liquid crystal disodium cromoglycate

“…The interest in the structural and rheological response of LCLCs to the applied shear is both practical and fundamental. LCLC materials can be used in applications such as sensors of microbial presence 32 , templates for alignment of graphene layers 33 , paintable polarizers 34,35 , organic field-effect transistors, 36 and optical compensators 16 . Preparation of the paintable polarizers, transistors, and optical compensators involves shear displacements of LCLCs with a simultaneous or subsequent drying.…”

About Supramolecular Assemblies of π-Conjugated Systems

“…509 Very recently, mixed chromonic liquid crystals of a quaterrylene bisimide (an extended rylene dye with four aromatic repeating units) with a functionalized perylene bisimide were reported. 510 The high orientation after alignment by shearing may prove useful in the implementation of these materials in liquidcrystal displays, since the fact that both components absorb at different wavelengths significantly broadens the spectral range over which the polarization principle is applicable. Supramolecular ordering of π-conjugated chromophores into efficient, electronic materials was reported by Percec et al, 511,512 who studied the selfassembly of various donor and acceptor dendrons into supramolecular columns (Figure 77).…”

Chromonic self-assemblies in a series of dialkyl-thiacarbocyanine dyes and generalization of a facile route for the synthesis of fluorescent nanostructured silica fibers

“…The phase sequence from N to M phase is in agreement with the one described by Lydon and observed in many water/chromonic systems. 10 The self-assembly behavior of dye molecules in solution into aggregated structures depends on the balance of intermolecular and inter-aggregate forces. Although it is known that this reflection is not well resolved in dilute systems, [38,39] it may also indicate a loose stacking at the concentrations studied or the presence of finite length stacks.…”

“…[9] interactions forming columns in an isodesmic-type assembly. Chromonic liquid crystals can be exploited in the production of aligned films, optical compensators, [10] biological sensing, [11] organic electronics, [12] and analytical methods. [13] Contrary to the conventional surfactant lyotropic liquid crystals, the behavior of chromonics is still not completely understood in terms of the effect of molecular architecture on their occurrence and properties.…”