• 제목/요약/키워드: liquid crystals

검색결과 442건 처리시간 0.021초

GH형 LCD에 있어서 액정 및 2색성 색소의 분자형상과 배향질서도와의 관계 (Relation between molecular structure and order parameter of liquid crystals and dyes in GH-LCD)

  • 박우상
    • E2M - 전기 전자와 첨단 소재
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    • 제10권10호
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    • pp.989-994
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    • 1997
  • In a Guest-Host cell the orientational ordering of dyes doped into liquid crystals has been investigated. To evaluate the influence of the host liquid crystals on the ordering of the dyes we have measured precisely the ordering parameters of the liquid crystals by using the dichroic ratio of the absorbances for infrared light polarized parallel and perpendicular to the diector. Our experimental results show that the ordering of the dyes can be expressed as a function of not only the molecular structure of the dyes but also the order parameter of the liquid crystals. These functions are dependent on the kinds of the liquid crystals and the dyes. Particularly the combination such as anthraquinone dyes doped into cyanobiphenyl liquid crystals show a very high ordering parameter. This is considered due to a strong intermolecular interaction between the dipoles of both liquid crystals and dyes.

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탄성 유체 윤활에서의 액정의 마찰 특성 및 유막두께 (Frictional Behavior and Film Thickness of Some Liquid Crystals in Elastohydrodynamic Lubrication)

  • 이희성
    • Tribology and Lubricants
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    • 제18권4호
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    • pp.255-259
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    • 2002
  • The tribological properties of eight different liquid crystals were investigated in a concentrated point contact device and a ball-on-flat contact. For comparison, the same tests were also performed with commercial greases and the corresponding base oils. Under the fully flooded conditions studied, liquid crystals in a concentrated point contact showed lower friction than commercial greases and greater film thickness dependence on rolling speed than grease base oils or greases. Test results also showed that the film thickness and friction were little influenced by the composition of the examined liquid crystals.

액정의 윤활특성에 관한 연구 (A Study on the Lubrication Characteristics of Liquid Crystals)

  • 임윤철;민지홍
    • Tribology and Lubricants
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    • 제8권1호
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    • pp.30-37
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    • 1992
  • The displacement and pressure field of liquid crystals are analyzed numerically and compared with classical Reynolds theory. A plane slider bearing is employed as a simple example considering elasticity, permeability and splay effect which are the inherent characteristics of layered liquid crystals. Due to the geometric constraint of thin wedge and the strong anchoring behavior of the liquid crystals dislocations are inevitable. A finite element method is used to solve five coupled nonlinear equations. The load characteristics based on the pressure distribution along the gap shows that the liquid crystals can carry large load compared to the conventional lubricants.

Recent Progress in Advanced LC Mixture Development for TFT LCD

  • Lee, Seung-Eun;Song, Dong-Mee;Kim, Eun-Young;Jacob, Thomas;Czanta, Markus;Manabe, Atsutake;Tarumi, Kazuaki;Wittek, Michael;Hirschmann, Harald;Rieger, Bernhard
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.159-162
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    • 2006
  • We reviewed our recent advances in LC mixture development identifying the new classes of materials to yield LC mixtures with faster switching times and better reliability

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Chain Length Dependence of Confined Liquid Crystals Configuration

  • Finotello, Daniele;Jin, Tao
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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    • pp.256-259
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    • 2003
  • The study of confined liquid crystals flourished in the decade of the nineties. Liquid crystals properties have been probed after confinement in well-defined or interconnected geometries as those available in porous media and in polymer networks. In this work we emphasized the power of the nuclear magnetic resonance technique to determine the confined liquid crystal structures. We also present unexpected results on the dependence of the confined liquid crystal configuration on the chain length.

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Chain Length Dependence of Confined Liquid Crystals Configuration

  • Finotello, Daniele;Jin, Tao
    • Journal of Information Display
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    • 제4권1호
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    • pp.14-16
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    • 2003
  • The study of confined liquid crystals flourished in the decade of the nineties. Liquid crystals properties have been probed after confinement in well-defined or interconnected geometries as those available in porous media and in polymer networks. In this work we emphasized the power of the nuclear magnetic resonance technique to determine the confined liquid crystal structures. We also present unexpected results on the dependence of the confined liquid crystal configuration on the chain length.

Dielectric and Electro-Optical Properties of Ceramic Nanoparticles Doped Liquid Crystals

  • Porov, Preeti;Chandel, Vishal Singh;Manohar, Rajiv
    • Transactions on Electrical and Electronic Materials
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    • 제17권2호
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    • pp.69-78
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    • 2016
  • Liquid crystals are important materials because of their applications in display technology and many other scientific applications. Different mixtures of liquid crystals and their doped samples have gained interest because a single liquid crystal compound cannot fulfill all the required parameters for the display application. The doping can be accomplished with dyes, polymers, or composite nanoparticles among other substance. The addition of nanoparticles can modify the physical properties of the host liquid crystal and enhances the performance of electro-optical devices. The present study is focused on investigations of possible changes in dielectric and electro optical properties of liquid crystals caused by doping with ceramic nanoparticles. Including smaller nanoparticles were found to be better candidates for use in suppressing the unwanted ion effects in liquid crystal displays.

Advanced Liquid Crystal Materials for Fast Switching Times

  • Jin, Min-Ok;Yoon, Dong-Kyu;Kim, Eun-Young;Lee, Seung-Eun;Heckmeier, M.;Klasen-Memmer, M.;Sem, G L;Tarumi, K.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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    • pp.1118-1120
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    • 2003
  • For LCD-TVs with full capability to show moving pictures and LCD monitors for multi media use, it is necessary that the switching times of Liquid Crystal (LC) mixtures are within one frame (16.7ms). In order to achieve faster switching times, new LC materials have been identified, mainly focusing on the further reduction of the rotational viscosity (${\gamma}1$).

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