화학공학소재연구정보센터
홈 로그인 로그아웃 연락처 사이트맵
Polymer(Korea), Vol.27, No.5, 484-492, September, 2003
Export Citation
폴리이미드-액정 계면의 특성에 따른 액정 배향의 특성 및 안정성
Characteristics and Stability of Liquid Crystal Alignment for Interfacial Properties of Polyimide-Liquid Crystal
동원석, 이미혜1, 백상현†
  • 경희대학교 환경응용화학대학 자연과학종합연구원, 용인 449-701
  • 1한국화학연구원 화학소재연구부, 대전 305-600
Wonseok Dong, Mi Hie Yi1, and Sang Hyon Paek†
  • Collage of Environment and Applied chemistry & Institute of Natural Sciences, Kyung Hee University, 1, Sochen-ri, Giheung-eup, Yongin 449-701, Korea
  • 1Advanced Materials Division, Korea Research institute of Chemical Technology, P.O. Box 107, Yusung, Daejeon 305-600, Korea
E-mail:
초록
러빙에 의해 유도된 네마틱 액정의 배향 특성과 그 안정성이 액정-폴리이미드 계면 특성과 어떠한 관계가 있는지를 조사하였다. 합성된 5종류의 폴리이미드 특성을 분석하고 폴리이미드 배향막에서의 액정 배향의 균일성, 선경사각, 정착 에너지, 그리고 열 안정성을 측정 조사하였다. 러빙된 폴리이미드는 강한 정착의 액정 배향을 유도하고 액정 배향의 특성과 안정성은 배향막 표면에서의 액정과 폴리이미드 간의 분자 차원의 상호작용에 의해 결정된다는 것을 확인하였다. 폴리이미드의 유연성의 증가는 이미드화를 촉진시키며 액정의 선경사각과 배향 안정성을 증대시킨다. 반면에, 폴리이미드의 플루오르화는 액정의 배향성 및 배향 안정성을 감소시키는 것으로 나타났다. 폴리이미드의 방향족과 지방족 고리 이무수물 구조에 따른 액정 배향의 특성과 안정성에는 뚜렷한 차이가 나타나지 않았다.
How the characteristics and stability of the rubbing-induced alignment of nematic liquid crystals (LCs) relate to the interfacial characteristics of LC-polyimide has been studied. The characteristics of the LC alignment (such as the LC texture, the pretilt angle, and the anchoring energy) and their thermal stability have been investigated for 5 polyimides synthesized for this work. The work showed that the rubbed polyimide alignment layer induces the strong LC anchoring and that the characteristics and stability of LC alignment are determined by the short-ranged interactions between LC and polyimide molecules at the alignment layer surface. The increased flexibility of the polyimide accelerates thermal imidization, increases the pretilt angle, and improves the alignment stability. It also turned out that fluorination of the polyimide tends to deteriorate the alignment uniformity and stability. No distinct differences in the alignment characteristics were shown for the aromatic- and alicyclic-dianhydride polyimides.
Keywords:polyimide;liquid crystal;alignment stability;pretilt angle;anchoring energy
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