Korean Chemical Engineering Research

The Korean Institute of Chemical Engineers (한국화학공학회)
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Electro-optic Properties of Polymer Dispersed Liquid Crystal Displays: Effect of BDVE(Butanediol Vinyl Ether) & Temprature Stability

고분자 분산형 액정 표시 소자(PDLC)의 제작 및 측정: BDVE(Butanediol Vinyl Ether) 첨가에 따른 효과와 온도의존성 평가

  • No, Young-Seok (Optoelectronic Devices Lab, School of Display and Chemical Engineering, Yeungnam University) ;
  • Jeon, Chan-Wook (Optoelectronic Devices Lab, School of Display and Chemical Engineering, Yeungnam University)
  • 노영석 (영남대학교 디스플레이 화학공학부 광전자소자 연구실) ;
  • 전찬욱 (영남대학교 디스플레이 화학공학부 광전자소자 연구실)
  • Received : 2007.09.20
  • Accepted : 2008.05.22
  • Published : 2008.10.31
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Abstract

The electro-optic properties of polymer-dispersed liquid crystal cells containing BDVE(Butanediol vinyl ether) in PN393 base pre-polymer were examined. The higher the contents of BDVE, the smaller becomes the droplet size. However, the droplet size was saturated around $3{\mu}m$ even at 40 wt% of BDVE. Both of contrast ratio and response time of PDLC cell fabricated with a new formula were found to be superior to the reference cell with PN393 by the factor of 4.9 and 0.15, respectively. However, the new formula made the operating voltage go higher compared to the reference cell of PN393 formula. Except for contrast ratio, response time as well as operating voltage were found to be highly stabilized by adding BDVE in PN393 base pre-polymer over the temperature range of $0{\sim}60^{\circ}C$ studied.

고분자 분산형 액정 표시 소자(PDLC)에 사용되는 pre-polymer인 PN393에 다량으로 함유된 반응성 모노머 2-ethylhexyl acrylate(EHA)를 비닐에테르 계열의 모노머인 butanediol vinyl ether(BDVE)로 대체하여 제작된 PDLC 셀의 전기 광학적 특성 변화를 알아보았다. BDVE 함량 30 wt%까지는 액정방울의 크기가 작아졌으나, 그 이상의 조성(40 wt%)인 경우, 더 이상의 액정방울크기 변화는 관찰되지 않았다. 명암비, 응답속도는 상용화된 PN393를 적용한 경우보다 각각 490%, 15%로 성능이 향상되었으나, 동작전압은 약 60% 증가하는 것으로 확인되었다. 전기광학적 특성 변화를 $0{\sim}60^{\circ}C$ 온도범위에서 관찰한 결과, 응답속도와 동작전압의 온도안정성은 향상되었으나, 명암비 성능은 온도증가에 따라 열화되는 것으로 확인되었다.

Keywords

Acknowledgement

Supported by : 영남대학교

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