title: Liquid crystal alignment on ion-beam-treated polyimide with a long alkyl side chain: near edge X-ray absorption fine structure spectroscopy analysis.
abstract: Liquid crystal alignment on ion-beam-treated polyimides with a long alkyl side chain was investigated using near edge X-ray absorption fine structure (NEXAFS) spectroscopy. The long alkyl side chains and the asymmetric distribution and orientational order of the pi-bonds of the polyimide surface can be determined by analyzing the angular dependent resonance intensities of the NEXAFS measurements. Herein, we demonstrate that the pretilt angle of the LC cell made by our method decreases as more long alkyl side chains are destroyed. Additionally, the tilt direction of the LC molecules can be determined from the asymmetric distribution of pi-bonds of the polyimide created by the ion beam irradiation.
authors.affiliation: School of Electrical Engineering, Pusan National University, Busan, 609-735, Korea.
authors.forename: Joo-Hong
authors.initials: JH
authors.lastname: Seo
authors.forename: Soo Won
authors.initials: SW
authors.lastname: Hwang
authors.forename: Dong Han
authors.initials: DH
authors.lastname: Song
authors.forename: Jae Hoon
authors.initials: JH
authors.lastname: Shin
authors.forename: Tae-Hoon
authors.initials: TH
authors.lastname: Yoon
authors.forename: Jae Chang
authors.initials: JC
authors.lastname: Kim
authors.forename: Mi Hye
authors.initials: MH
authors.lastname: Yi