• Journal of Information Display
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• 제7권1호
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• pp.7-11
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• 2006

In this paper, we report the fabrication of high quality polymer walls by using a monomer containing fluorine (F-monomer). Polymer walls with no phase retardation were fabricated by using photo-polymerization induced anisotropic phase separation of the mixture composed of liquid crystal (LC) and F-monomer. Thanks to the immiscibility of fluoride, we could form high quality polymer walls with no light leakage. We measured electro-optic characteristics of a twisted-nematic (TN) LC cell whose polymer walls were fabricated by using the F-monomer, and the measurements were compared with that fabricated by using the monomer without fluorine.

• Fibers and Polymers
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• 제1권2호
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• pp.83-91
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• 2000

Thermotropic liquid crystalline polymer made up of poly(p-hydroxybenzoate) (PHB)-poly(ethylene terephthalate)(PET) 8/2 copolyester, poly(ethylene 2,6-naphthalate) (PEN) and PET were mechanically blended to pursue the liquid crystalline phase of ternary blends. Complex viscosities of blends decreased with increasing temperature and PHB content. DSC thermal analysis indicated that glass transition temperature (Tg) and melting temperature (Tm) of blends increased with increasing PHB content. Both tensile strength and initial modulus increased with raising PHB content and take-up speed of monofilaments. In the WAXS diagram, only PEN crystal reflection at 2Θ=$15.5^{\circ}C$ appeared but PET crystal reflection was not shown in all compositions. The degree of transesterification and randomness of blends increased with blending time but sequential length of both PEN and PET segment decreased.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.194-195
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• 2002

We report a fast-switching polymer-stabilized bend nematic (PSBN) device. The morphology study reveal a templated polymer networks captures the orientation of the field deformed nematic host.

• Journal of Information Display
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• 제4권3호
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• pp.26-28
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• 2003

In the paper, we investigated the Bragg reflective cholesteric display based on polymer stabilization. We studied the bistability in the polymer stabilized cholesteric texture (PSCT) films and baused on which we achieved wider viewing angle though imperfect planar texture.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.1130-1131
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• 2006

Here we report the effect of photo-spacer and polymer wall on the mechanical stability of the polymer-stabilized ferroelectric liquid crystal (PSFLC) system. A better bending tolerance of the PSFLC cell was obtained when the polymer wall was formed parallel to the rubbing direction. In addition, the effect of the distance between photo-spacer columns as well as that of the distance between polymer wall columns on the mechanical stability of the liquid crystal was examined.

• 공업화학
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• 제9권1호
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• pp.71-75
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• 1998

LCD용의 재료로 사용하기 위하여 새로이 합성된 저분자 액정 중간체들을 이용하여 epoxy resin 구조를 근간으로 하는 측쇄형 선형액정 고분자 및 가교된 측쇄형 액정 고분자를 만들고 이 들의 액정특성에 대하여 조사하였다. Alkyl spacer의 길이가 다른 방향족 amine 말단의 방향족 저분자 액정(ALC(n))과 ethylene glycol diglycidylether로부터 합성된 선형 측쇄형 고분자액정은 DSC 및 편광현미경 관찰로부터 mesogen으로 쓰인 저분자 액정과 같이 네마틱 액정상을 보였으며 spacer $-(CH_2){_n}-$의 길이에 따라 액정상-등방상 전이온도($T_{NI}$)는 even-odd현상을 나타내었다. 선형 및 가교형 측쇄 액정고분자의 $T_{NI}$는 저분자 액정의 그것에 비해 더 낮은 온도에서 나타났으며 또한 가교형 측쇄 액정고분자의 경우에는 가교제인 1,10-diaminodecane 사용량에 따른 $T_g$및 $T_{NI}$의 변화폭이 그렇게 크지 않은 것이 관찰되었다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.616-619
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• 2009

Color tracking behavior of in the fringe-field switching (FFS) mode using a liquid crystal with positive dielectric anisotropy has been studied. In the in-plane switching and vertical alignment devices, color chromaticity at normal direction changes from bluish to yellowish white linearly with increasing grey levels from dark to white state. Interestingly, abnormal behavior in color tracking is observed in FFS devices using a liquid crystal with positive dielectric anisotropy, that is, it changes from bluish to yellowish up to a certain middle grey level but turns over to bluish white with further increasing from a grey level to a fully white state. In this paper, we analyze this abnormal effect from the calculated and experimental results.

• 한국인쇄학회지
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• 제13권2호
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• pp.19-32
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• 1995

Liquid crystal-polymer composite(LCPC) films are promising new materials for both projection displays and vision products. LCPC films consist of a continuous liquid crystal phase embedded in a three- dimensional network of polymer matrix. The liquid crystal in these LC phases can be electrically switched giving rise to an opaque scattering off-state and a transparent, non- scattering on-state. In this work, a premixture is composed of LC, UV-curable monomer and photonitiator. LCPC films are formed by photopolymerization induced phase separation from this premixture. In conclusion, structure and electro-optical properties of LCPC films strongly depends on the selection of monomer, LC content and curing rate.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.1447-1449
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• 2009

We report the syntheses bis-(N,N-diethylaminoethyl) perylene-3,4,9,10-tetracarboxylic diimide (PDI) of lyotropic chromonic liquid crystal and it dissolves in photocurable ionic monomer solution. PDI-acrylic acid solution was observed whether liquid crystal phase appeared in each concentration. Thin film polarizer was prepared by simultaneously coating and aligning the solution of PDI-acrylic acid (in the chromonic nematic phase) onto glass substrates using a mechanical shearing force and was cured by irradiation of UV light. Also Photopatterned polarizer is manufactured by same process.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.902-903
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• 2009

Polymer Dispersed Liquid Crystal (PDLC) films were prepared using the phase separation method with liquid crystal and a newly developed prepolymer. This study investigated the electro-optic characteristics of the PDLC film at various temperatures. It was found that as temperatures increased, the voltage varied, and that the ordinary refractive index of the liquid crystal and the polymer refractive index in the composite had similar dependence at various temperatures.