• Title/Summary/Keyword: Homeotropic alignment

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Alignment Effect of a Nematic Liquid Crystal on Deposited SiOx Thin-Film Surface with e-beam Evaporation

  • Oh, Yong-Cheul;Lee, Dong-Gyu
    • Transactions on Electrical and Electronic Materials
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    • v.7 no.6
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    • pp.305-308
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    • 2006
  • We have studied liquid crystal (LC) aligning capabilities for homeotropic alignment and the control of tilt angles on the $SiO_{x}$ thin film by electron beam evaporation method. A high tilt angle of about $86.5^{\circ}$ was obtained, and also the suitable tilt angle of the NLC on the $SiO_{x}$ thin film at $20{\sim}50\;nm$ thickness with e-beam evaporation can be achieved. The uniform LC alignment on the $SiO_{x}$ thin film surfaces with electron beam evaporation can be achieved. It is considerated that the LC alignment on the $SiO_{x}$ thin film by electron beam evaporation is attributed to elastic interaction between LC molecules and micro-grooves at the $SiO_{x}$ thin film surface created by evaporation.

LC Aligning Properties for Homeotropic Alignment of NLC on the SiOx Thin Film as Incident Angle of Electron Beam Evaporation Angle

  • Kim, Jong-Hwan;Kang, Hyung-Ku;Han, Jin-Woo;Kang, Soo-Hee;Kim, Young-Hwan;Hwang, Jeoung-Yeon;Seo, Dae-Shik
    • Transactions on Electrical and Electronic Materials
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    • v.7 no.1
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    • pp.21-25
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    • 2006
  • In this study, liquid crystal (LC) aligning properties for homeotropic alignment on the $SiO_x$ thin film by electron beam evaporation method with electron beam system in accordance with the evaporation angles were investigated. Also, the control of pretilt angles homeotropic aligned LC on $SiO_x$ thin film as the function of the evaporation angles were studied. The uniform vertical LC alignment on the $SiO_x$ thin film surfaces with electron beam evaporation was achieved with all of the thin film angle conditions. It is considerated that the LC alignment on the $SiO_x$ thin film by electron beam evaporation is attributed to elastic interaction between LC molecules and micro-grooves at the $SiO_x$ thin film surface created by evaporation. The values of the pretilt angles according to the evaporation angle were from about $0.7^{\circ}$ to about $3.4^{\circ}$. The highest pretilt angles of about $3.4^{\circ}$ in aligned NLC on the $SiO_x$ thin film surfaces by electron beam evaporation were measured under the condition of $45^{\circ}$. Also, good LC alignment states on the treated $SiO_x$ thin film layer by electron beam evaporation were observed at annealing temperature of $250^{\circ}C$. Consequently, the high pretilt angle and the good thermal stability of LC alignment on the $SiO_x$ thin film by electron beam evaporation can be achieved.

Liquid crystal alignment effect and synthesis of photo-polymer material containing cholesteryl moiety for homeotropic alignment (Cholesteryl 기를 함유한 수직배향용 광폴리머 재료의 합성 및 배향 효과)

  • 황정연;서대식;한은주
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.13 no.9
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    • pp.770-775
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    • 2000
  • A new photo-polymer material of the copoly (PM4Ch-ChMA), copoly (poly (4-methacryloyloxy)chalcone-cholesteryl methacrylate) for homeotropic alignment was synthesized and the electro-optical (EO) performance for the photo-aligned vertical-aligned (VA)-LC display (LCD) was studied. Good thermal stabilities of synthesized copolymer were obtained by TGA(Thermogravimetric Analysis) measurement. Good voltage-transmittance (V-T) and response time characteristics for the photo-aligned VA-LCD with polarized UV exposure in oblique direction($\theta$$_{i}$=30$^{\circ}$) on a copolymer-1 (2%) surfaces for 1 min were observed. but, light leakage in the off-state was observed. Therefore, we achieved excellent V-T and response time characteristics for the photo-aligned VA-LCD with UV exposure on a copolymer-3 (30%) surfaces for 3 min.n.

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Liquid Crystal Aligning Capabilities on Homeotropic Blending Polyimide Layer (수직 복합 폴리이미드층에서의 액정 배향 특성)

  • Hwang, Jeoung-Yeon;Seo, Dae-Shik;Kim, Jae-Hyung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11b
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    • pp.337-340
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    • 2001
  • The control of high pretilt angle far nematic liquid crystal (NLC) with negative dielectric anisotropy on the rubbed blending polyimide (homeotropic and homogeneous alignment) surface were studied. High NLC pretilt angle generated on the blending polyimide (homeotropic polyimide and SE-7492 surface was measured and the NLC pretilt angle increases with blending ratio and rubbing strength. However, the NLC pretilt angle generated on the blending polyimide (homeotropic polyimide and SE-150 surface was not varied. The high pretilt angle the NLC using blending polyimide surface can be acheived.

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Liquid Crystal Aligning Capabilities on Homeotropic Blending Polyimide Layer (수직 복합 폴리이미드층에서의 액정 배향 특성)

  • 황정연;서대식;김재형
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11a
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    • pp.337-340
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    • 2001
  • The control of high pretilt angle for nematic liquid crystal (NLC) with negative dielectric anisotropy on the rubbed blending polyimide (homeotropic and homogeneous alignment) surface were studied. High NLC pretilt angle generated on the blending polyimide (homeotropic polyimide and SE-7492 surface was measured and the NLC pretilt angle increases with blending ratio and rubbing strength. However, the NLC pretilt angle generated on the blending polyimide (homeotropic polyimide and SE-150 surface was not varied. The high pretilt angle the NLC using blending polyimide surface can be achieved.

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Pretilt Angle Properties of Mixture Nematic Liquid crystal for Mobile Information Device (휴대용 통신단말에 사용되는 혼합액정계에서의 프리틸트각 특성에 관한 연구)

  • Han, Jeongmin;Seo, Daeshik
    • Journal of Satellite, Information and Communications
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    • v.10 no.1
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    • pp.67-70
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    • 2015
  • We studied the state of the dual liquid crystal (LC) alignment which displays both homeotropic and homogeneous alignment on blended polyimide (PI) layer. The research was conducted using rubbing method at different imidizing temperatures and the blended PI was made using homeotropic PI having an alkyl side chain and homogeneous PI without the side chain. The uniform LC alignments were achieved, and have thermal stability. The results of contact angles were similar to that of pretilt angles.

Homeotropic Alignment Effect of a Nematic Liquid Crystal on Oblique Deposited SiOx Thin-film with e-beam Evaporation

  • Choi, Dai-Seub
    • Transactions on Electrical and Electronic Materials
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    • v.8 no.6
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    • pp.274-277
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    • 2007
  • In this study, liquid crystal(LC) aligning capabilities for homeotropic alignment on the $SiO_x$ thin film by electron beam evaporation method were investigated. Also, the control of pretilt angles and thermal stabilities of the nematic liquid crystal(NLC) treated on $SiO_x$ thin film were investigated. A high pretilt angle of about $86.5^{\circ}$ was obtained, and also the suitable pretilt angle of the NLC on the $SiO_x$ thin film at $10{\sim}50nm$ thickness with e-beam evaporation can be achieved. The uniform LC alignment and good thermal stabilities on the $SiO_x$ thin film surfaces with electron beam evaporation can be achieved. It is considered that the LC alignment on the $SiO_x$ thin film by electron beam evaporation is attributed to elastic interaction between LC molecules and micro-grooves at the $SiO_x$ thin film surface created by evaporation.

Homeotropic Alignment Effect for Nematic liquid Crystal on the Treated $SiO_x$ Thin Film Layer by Sputtering Method (스퍼터링법으로 경사증착한 $SiO_x$ 박막 표면의 액정 수직 배향 효과)

  • Choi, Sung-Ho;Kim, Byoung-Young;Kim, Young-Hwan;Kim, Jong-Hwan;Han, Jung-Min;Hwang, Jeoung-Yeon;Oh, Byeong-Yun;Myoung, Jae-Min;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.04a
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    • pp.66-67
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    • 2006
  • We studied nematic liquid crystal (NLC) alignment effect on the $SiO_x$ thin film deposited $45^{\circ}$ oblique by rf magnetic sputtering system. Pretilt angle and thermal stability characteristic as well as NLC alignment effect were investigated. A uniform liquid crystal alignment effect on the $SiO_x$ thin film was achieved and pretilt angle was about $90^{\circ}$. The thermal stability of the $SiO_x$ thin film was sustained by $200^{\circ}$.

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Electro-Optical Characteristic for VA-LCD on the $SiO_x$ Thin Film Layer Oblique Deposited by Sputtering Method (스퍼터링으로 경사증착한 $SiO_x$ 박막을 이용한 VA-LCD의 전기광학특성)

  • Choi, Sung-Ho;Hwang, Jeoung-Yeon;Kim, Sung-Yeon;Oh, Byeong-Yun;Myoung, Jae-Min;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.06a
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    • pp.451-452
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    • 2006
  • We studied the electro-optical characteristic of vertical alignment liquid crystal display(VA-LCD) on the $SiO_x$ thin film deposited $45^{\circ}$ oblique by rf magnetic sputtering system. LC alignment characteristic showed homeotropic alignment, and pretilt angle was about $90^{\circ}$. A uniform liquid crystal alignment effect on the $SiO_x$ thin film was achieved and the electro-optical characteristic of the $SiO_x$ thin film deposited $45^{\circ}$ oblique by rf magnetic sputtering system was excellent.

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Control of High Pretilt Angle for Nematic Liquid Crystal of Negative Dielectric Anisotropy on Blending Polymer Surfaces (복합 폴리머 표면에서의 부의 유전율을 가진 네마틱액정의 고프리틸트각 제어)

  • 황정연;서대식;남상회
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.14 no.12
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    • pp.1023-1026
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    • 2001
  • The control of high pretilt angle for nematic liquid crystal (NLC) with negative dielectric anisotropy on the rubbed blending polyimide (PI) of homeotropic and homogeneous alignment surface was studied. High LC pretilt angle on the rubbing blending polyimide of homeotropic PI and SE-7492 surface was measured and the LC pretilt angle increased wish blending ratio and rubbing strength. However, the low LC pretilt angle on the rubbed blending polyimide of homeotropic PI and SE-150 surface was measured. The high pretilt angle of NLC can be achieved by using the blending PI surface.

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