# Photoalignment at the nematic liquid crystal - polymer interface: experimental evidence of three-dimensional reorientation

## TL;DR

This study provides experimental evidence that photoalignment at the nematic liquid crystal-polymer interface involves complex three-dimensional reorientation influenced by mutual interactions and temperature-induced transitions, challenging simpler two-dimensional models.

## Contribution

It demonstrates that photoalignment is a coupled three-dimensional process affected by both materials and temperature, offering new insights into the mechanism.

## Key findings

- Photoalignment involves 3D reorientation, not just 2D.
- The polymer and NLC layers mutually influence each other.
- Temperature-induced anchoring transitions are significant.

## Abstract

We provide experimental evidence that photoalignment at the nematic liquid crystal (NLC) - polymer interface can not be simply considered as a two-dimensional process. Moreover, our experiments clearly indicate that the photoaligning process does not depend on the individual properties of the NLC material and those of the interfacing polymer exclusively. According to our measurements, the polymer and the NLC layer "sense-each-other", i.e., the polymer-liquid crystal interface should be regarded as a coupled system, where the two components mutually influence each other. Furthermore, we show that the temperature induced anchoring transition also has to be taken into account for the complete description of the photoalignment mechanism.