Waterproof material for liquid crystals photoalignment based on azo dyes

Abstract

We have designed and synthesized azo dyes with reversible intermolecular bonds, which can be used as materials for liquid crystal photoalignment. The generation of anisotropic structures in azo dye thin film is possible due to the presence of intermolecular hydrogen or coordination (metal–oxygen) bonds. All thin film materials are resistant to air moisture, while photoalignment material with reversible hydrogen bonds is inert to direct water contact. In this paper, we study photoalignment dynamics of obtained materials and discuss possible formation of intramolecular and intermolecular hydrogen bonds within the photoalignment dye layer.

Geometric phase ando-mode blueshift in a chiral anisotropic medium inside a Fabry-Pérot cavity

“…The main drawback of the presented scheme is that untwisted structure maintains a constant RI for the o-polarized light only. The e-polarized spectral shift may be measured in the experimental scheme with the twistplanar to homogeneous-planar transition, which could be achieved using photoalignment material with reversible intermolecular bonds [89,90].…”

Electrically controlled spatial-polarization switch based on patterned photoalignment of nematic liquid crystals

“…The photoalignment technique is used to set the required initial orientation of the LC molecules [23][24][25]. The photosensitive alignment material is represented by the water-insoluble azo dyes (3), synthesized at the Institute of Chemistry of New Materials of the Belarusian National Academy of Sciences, which are characterized by high anchoring energy, thermostability, photostability, and insensitivity to moisture treatment [26]. Under the effect of polarized light, the dye layer forms a linear molecular structure that aligns the LC.…”

P‐115: New Photoalignment Material: Azimuthal Anchoring Energy Decreases at Very High Photo‐Induced Order Parameters

“…We have already obtained over 40 new structures of azo-dyes with confirmed photoalignment properties and solved a number of technological problems related with application of azodyes, such as photosensitivity increase [7], moisture sensitivity [8] and other. In the present paper we address the problem of maximization of azimuthal anchoring energy of the azo-dye photoalignment layer.…”