Surface alignment and anchoring transitions in nematic lyotropic chromonic liquid crystal

TL;DR

This paper investigates the surface alignment behaviors of lyotropic chromonic liquid crystals, revealing transitions between homeotropic and tangential states driven by anchoring potential changes.

Contribution

It demonstrates the existence of discontinuous anchoring transitions and models them using a double-well potential, advancing understanding of LCLC surface behaviors.

Findings

Homeotropic alignment can switch to tangential over time.

Anchoring transition is discontinuous and described by a double-well potential.

Optical retardation and 3D imaging reveal director field configurations.

Abstract

The surface alignment of lyotropic chromonic liquid crystals (LCLCs) can be not only planar (tangential) but also homeotropic, with self-assembled aggregates perpendicular to the substrate, as demonstrated by mapping optical retardation and by three-dimensional imaging of the director field. With time, the homeotropic nematic undergoes a transition into a tangential state. The anchoring transition is discontinuous and can be described by a double-well anchoring potential with two minima corresponding to tangential and homeotropic orientation.