Oriented Monolayers Prepared from Lyotropic Chromonic Liquid Crystal

Abstract

We use a layer-by layer electrostatic self-assembly technique to obtain in-plane oriented aggregates of mesogenic dye molecules cast from lyotropic chromonic liquid crystals (LCLCs) on mica substrates. The aqueous solutions of dye used for deposition are in the nematic phase. Atomic force microscopy and X-ray photoelectron spectroscopy of the dried film reveal that the LCLC molecules adsorb at the charged substrate preserving ordered aggregates of elongated shape characteristic of the nematic phase in the aqueous solution. These elongated aggregates of LCLC molecules form films with in-plane orientational order and are compositionally distinct from the substrate.

Polymer‐Stabilized Chromonic Liquid‐Crystalline Polarizer

“…When the LCLC molecules are oriented at a specific direction, the macroscopically oriented crystalline film can exhibit anisotropic optical and electrical properties 17–19. Since charge carriers can more effectively travel along the long axis of columns, the oriented LCLC crystalline films exhibit electrical anisotropies and hence can be applied in photovoltaics and electronic devices 20, 21. Moreover, many LCLC materials can absorb light in the visible and near‐infrared range because of the aromatic core.…”

Lyotropic chromonic liquid crystal semiconductors for water-solution processable organic electronics

“…The orientational order with dense packing is preserved when the aggregates are transferred from the nematic water solutions into thin films by shear deposition and drying. [13][14][15][16][17] Titled alignment of LCLCs is hindered by the aggregate structure; 18 thus the proper planar alignment can be achieved without special aligning layers. We show that dry aligned films of LCLC exhibit semiconducting properties with anisotropic mobility of charge carriers that is maximum along the aggregates.…”

“…19 The nematic phase was formed in aqueous solutions with a concentration of 7.4-8.0 wt %. 14 The solution was deposited onto the substrates and shear-aligned using either a vertical spin-coating ͑1500 rpm͒ ͑Ref. 20͒ or an applicator rod.…”

Charge carrier trapping in highly-ordered lyotropic chromonic liquid crystal films based on ionic perylene diimide derivatives

“…The resulting aggregates are of columnar type as the planes of the molecules form stacks (rather than closed micelles common in amphiphilic systems). An aqueous solution of Per-2582SL (concentration of about 8 wt.%) was prepared in order to obtain a nematic phase [35]. The solution was deposited on a substrate and shear-aligned using the so-called "vertical" spin-coating technique (1500 rpm) [19,36].…”