Polyamic Acid Langmuir-Blodgett Film for Liquid Crystal Alignment

Abstract
A method to prepare polyamic acid Langmuir-Blodgett (LB) film has been established for a nematic liquid crystal alignment layer. It consists of two steps: (1) LB deposition of polyamic acid alkylamine salt, and (2) conversion of the LB film obtained to polyamic acid LB film by removing the alkylamine by immersion in acetic anhydride. The present LB film shows an excellent ability for nematic liquid crystal alignment without the conventional rubbing process.