• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.921-923
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• 2002

Vertically Aligned (VA) technology is an advanced technology for TFT-LCDs, which is mainly used in larger size displays like monitors for desktop computers and even for TVs. We will review our recent developments of Liquid Crystal (LC) mixtures for VA display modes.

• Journal of Information Display
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• 제13권4호
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• pp.145-149
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• 2012

Liquid crystals are useful for a wide range of applications due to their exceptional properties. Doping of liquid crystals with carbon nanotubes (CNTs), even at very low concentrations, produces a detectable effect on the liquid crystal (LC) properties that can be very attractive for various functions. In this study, an attempt was made to investigate the effect of CNTs on the electrical properties of a short-pitch and high-spontaneous-polarization ferro-electric LC mixture, FLC-6304, at different temperatures. The inclusion of the CNTs significantly reduced the polarization at temperatures well within the $SmC^*$ phase, but the effect was gradually reversed as the transition temperature was approached. The insertion of the CNTs also reduced the response time and the rotational viscosity of the FLC mixture, which is highly desirable in the LCD industry.

• 충청수학회지
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• 제36권1호
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• pp.25-37
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• 2023

In this paper, we consider the Landau-de Gennes energy functional for liquid crystals confined in a thin cylindrical domain and study defects of molecular directions in the system by applications of external fields.

• Transactions on Electrical and Electronic Materials
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• 제16권3호
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• pp.117-123
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• 2015

Cholesteric liquid crystals are one dimensional photonic band-gap materials due to their birefringence and periodic structure. Dye doped cholesteric liquid crystals are self-assembling, mirror-less, low threshold laser structures that exhibit distributed feedback. In this review paper, we have presented the development in the field of lasing characteristics of dye doped cholesteric liquid crystals.

• Journal of Radiation Protection and Research
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• 제30권1호
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• pp.27-30
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• 2005

New possibilities are discussed for cholesteric liquid crystals (CLC) as sensor materials for detection of ionizing radiation, biologically active UV radiation, and the presence of hazardous vapors in atmosphere. A distinguishing property of CLC-based detectors is their 'bioequivalence', i.e., mechanisms of their response to external factors essentially imitate the corresponding mechanisms of biological tissues. Such detectors can ensure sufficiently high sensitivity to make feasible their use as alarm indicators or in biophysical studies. Specific examples ate given of sensor compositions and their response characteristics.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.757-761
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• 2004

Flat Panel Display (FPD) application of Television (TV) application is booming. Liquid Crystal Display (LCD) is forecasted to play a dominant role for TV application in next years. We review in this presentation LC material development for LCD TV application.

• 충청수학회지
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• 제31권1호
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• pp.193-197
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• 2018

In this paper, we consider a simplified energy functional for ferroelectric liquid crystals. With a special ansatz, we study existence of local minimizer with a certain symmetry.

• 폴리머
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• 제35권5호
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• pp.493-498
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• 2011

Reactive mesogen인 광경화성 액정은 광반응에 의해 분자들이 네트워크 구조를 형성하여 초기 액정 분자들의 배향을 유지한 상태로 필름을 만들 수 있다. 광경화성의 reactive mesogen과 광반응 그룹이 없는 네마틱 액정을 혼합하여 경화 전과 후의 액정 혼합물의 배향을 비교하였고, 비반응성 네마틱 액정의 양과 온도에 따른 액정필름의 복굴절 변화를 조사하였다. 네마틱 액정의 양에 따라 복굴절이 다른 필름을 얻을 수 있어 reactive mesogen을 이용한 광학 보상필름 응용 가능성을 확인하였다.

• Macromolecular Research
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• 제14권2호
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• pp.155-165
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• 2006

The present article describes the experimental and theoretical observations on the formation of holographic, polymer-dispersed, liquid crystals and electrically switchable, photonic crystals. A phase diagram of the starting mixture of nematic liquid crystal and photo-reactive triacrylate monomer was established by means of differential scanning calorimetry (DSC) and cloud point measurement. Photolithographic patterns were imprinted on the starting mixture of LC/triacrylate via multi-beam interference. A similar study was extended to a dendrimer/photocurative mixture as well as to a single component system (tetra-acrylate). Theoretical modeling and numerical simulation were carried out based on the combination of Flory-Huggins free energy of mixing and Maier-Saupe free energy of nematic ordering. The combined free energy densities were incorporated into the time-dependent Ginzburg-Landau (Model C) equations coupled with the photopolymerization rate equation to elucidate the spatio-temporal structure growth. The 2-D photonic structures thus simulated were consistent with the experimental observations. Furthermore, 3-D simulation was performed to guide the fabrication of assorted photonic crystals under various beam-geometries. Electro-optical performance such as diffraction efficiency was evaluated during the pattern photopolymerization process and also as a function of driving voltage.

• 폴리머
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• 제34권3호
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• pp.242-246
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• 2010

선택 반사를 보이는 콜레스테릭 액정의 planar 배열과 선택적 반사 효율과의 연관성에 대하여 FTIR spectroscopy를 이용하여 정량적으로 조사하였다. Cholesteric liquid crystal(CLC) 내 planar 배열이 잘 유도될수록 선택 반사율이 높아짐을 알 수 있었고, 배향막을 사용하지 않고 shear force 효과에 의해서만 planar 배열을 유도할 수 있었지만 완전한 planar 배열을 유도하기 위해서는 배향막을 사용하는 것이 효과적이었다.