• Title/Summary/Keyword: 분자분극의 이방성

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The Explicitly Quasi-linear Relation Between the Order Parameter and Normalized Birefringence of Aligned Uniaxially Anisotropic Molecules Determined Using a Numerical Method (수치해석적인 방법으로 규명한 정렬된 단축이방성 분자들의 질서변수와 상대 복굴절의 준선형 관계식)

  • Kim, Sang Youl
    • Korean Journal of Optics and Photonics
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    • v.27 no.6
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    • pp.223-228
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    • 2016
  • The birefringence of distributed, uniaxially anisotropic molecules like liquid crystals is calculated as the degree of ordering is varied. The relation between the normalized birefringence ${\Delta}n_{rel}$ and the orientational order parameter S is investigated. The distribution function, which enables one to monitor the degree of ordering of liquid crystals including randomly distributed ones, is introduced. Using this distribution function, a series of distributed liquid crystals with order parameters ranging from 0 to 1 are generated, and ${\Delta}n_{rel}$ and S of the correspondingly distributed liquid crystals are calculated. Based on the calculated data, it is revealed that ${\Delta}n_{rel}$ and S satisfy the quasi-linear relation of $S=(1+a){\Delta}n_{rel}-a{\Delta}n^2_{rel}$, where a can be approximated as $n_o{\frac{{\Delta}n}{4}}$. The anisotropy of molecular polarizability is also calculated, using the birefringence, and separately following Vuks' method and Neugebauer's method, and it is shown that the relations between S and the molecular-polarizability anisotropy are also quasi-linear.

Synthesis of trans, trans-4-(2-Fluoro-3-isothiocyanato-4-propylphenyl)-4-alkylbicyclohexyl for Liquid Crystal Display (액정 디스플레이를 위한 트랜스, 트랜스-4-(2-플르로로-3-아이소싸이오싸이아네이토-4-프로필페닐)-4'-알킬바이싸이클로헥실의 합성)

  • Lee, Seon-Hui;Kim, Seong-Hun
    • Journal of the Korean Chemical Society
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    • v.48 no.5
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    • pp.499-503
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    • 2004
  • We designed and synthesized compounds which have negative dielectric anisotropy (N type) for VA-LCD mode. Due to the large dipole moments toward the minor axis of molecule and anisotropy of polarizability, they can be used as N type LC. F atom and NCS group and propyl group were introduced as substituents on bicyclohexylbenzene core unit and alkyl chains (propyl~heptyl) were introduced on terminal part. All of the synthesized compounds showed negative dielectric anisotropy as expected.