Preparation of Optically Anisotropic Film by Sunset Yellow Chromonic Liquid Crystal

Sunset Yellow 액정 색소를 이용한 광학적 이방성 필름 제조

  • Kim, Byungchul (Korea Institute of Industrial Technology (KITECH)) ;
  • Chang, Eugene (Korea Institute of Industrial Technology (KITECH)) ;
  • Shin, Seunghan (Korea Institute of Industrial Technology (KITECH))
  • 김병철 (한국생산기술연구원 청정생산기술연구부) ;
  • 장유진 (한국생산기술연구원 청정생산기술연구부) ;
  • 신승한 (한국생산기술연구원 청정생산기술연구부)
  • Received : 2010.10.19
  • Accepted : 2010.12.14
  • Published : 2011.02.10

Abstract

The aqueous solution of Sunset Yellow-FCF (SY-FCF) began to show schlieren texture at room temperature when its concentration reaches 25 wt%. A further increase of the concentration of SY-FCF to 28 wt% resulted in a perfect nematic liquid crystal phase. However, more than 30 wt% of SY-FCF in aqueous solution was required to make an optically anisotropic film simply by shear coating. In our study, concentration of SY-FCF solution, coating speed, drying temperature, and relative humidity were considered as coating parameters affecting the preparation of optically anisotropic thin films. From analysis of variance analysis (ANOVA), the solution concentration was revealed as a main factor affecting the film thickness. The drying temperature and solution concentration were main factors affecting the transmittance of parallel direction ($T_o$). Especially, SY-FCF aqueous solution with high concentration induced a better alignment of LC columns and produced highly oriented anisotropic films. In this study, optically anisotropic films prepared by 33 wt% of SY-FCF in aqueous solution showed 89.7~98.7% of degree of polarization.

Acknowledgement

Supported by : 지식경제부

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