Liquid Crystal Alignment Properties on Zirconia Doped Polyimide Layer

Abstract

This paper introduces zirconia (ZrO₂) use in liquid crystal (LC) alignment for uniform and effective LC orientation. We used a conventional rubbing process to induce LC alignment. As a result, uniform LC alignments were achieved in all samples with ZrO₂ nanoparticles from 0.01 wt% to 0.3 wt%. Pretilt angles of LCs on ZrO₂ nanoparticles doped LC alignment layers slightly increased as the percentage of ZrO₂ nanoparticles rose. However, contact angles were almost the same. When twist-nematic (TN) LC cells used LC alignment layers with ZrO₂ nanoparticle content of 0.1 wt%, best performance was shown. Finally, it is shown that ZrO₂ nanoparticles doped LC alignment layers have more thermal budget than pristine ones in thermal stability test.

Keywords:

• ZrO₂ nanoparticle
• rubbing
• liquid crystal alignment
• doping concentration

Acknowledgment

This research was supported by the MKE (The Ministry of Knowledge Economy), Korea, under the ITRC (Information Technology Research Center) support program supervised by the NIPA (National IT Industry Promotion Agency) (NIPA-2011-C1090-1111-0002).