Poly(styrene–maleic anhydride) films as alignment layers for liquid crystal systems via ion-beam irradiation

Abstract

We report an investigation of poly(styrene–maleic anhydride) (SMA) films as liquid crystal (LC) alignment layers fabricated by ion-beam (IB) irradiation. We confirmed that SMA-deposited LC cells have superior optical properties by measuring the transmittance and phase differences. Using an IB-irradiated SMA film for the alignment layer, we could confirm that uniform and homogeneous LC alignment was achieved, yielding extremely high-performance nematic liquid crystal (NLC) systems. The LC alignment mechanism was determined by X-ray photoelectron spectroscopy. IB irradiation caused chemical modifications that led to strong van der Waals forces between LCs and the modified SMA surface, thereby inducing uniform LC alignment. Moreover, the IB-irradiated SMA films exhibited good electro-optical characteristics. Therefore, these IB-irradiated SMA films are suitable as alternative alignment layers for LC display applications.