• Electrical & Electronic Materials
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• v.10 no.1
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• pp.68-75
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• 1997

본 해설에서는 평판 디스플레이 소자중의 하나인 LCD의 액정배향기술에 관하여 해설하였다. 액정배향은 LCD의 전기광학특성을 좌우하는 매우 중요한 기술이다. LCD 소자에 있어서 기판의 표면 위에 액정분자를 배열시키는 기술은 현재 러빙법이 주로 사용되고 있지만 러빙을 하지 않는 넌러빙법을 이용한 액정배향기술이 강하게 요구되고 있으며 향후 LCD에 있어서 보다 중요한 역할을 할 것으로 기대되고 있으며 고성능 LCD의 실현에는 필수 불가결한 기술로 생각된다.

• Proceedings of the Korean Fiber Society Conference
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• 1998.10a
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• pp.244-247
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• 1998

고분자 물질의 물리적 성질은 물질의 화학적 구조뿐만 아니라 분자의 배향과 결정화도와 같은 내부 구조에 의해 크게 영향을 받는다. 상업적으로 생산되는 대부분의 고분자 물질은 강도와 치수 안정성 둥의 물리적 성질을 향상시키기 위해 연신과 annealing의 공정을 통해 분자의 배향과 결정화도를 증가시킨다. 따라서 고분자 물질의 물리적 성질을 이해하기 위해서는 연신과 annealing의 공정에서 수반되는 분자의 배향과 결정화 거동의 내부 구조 변화에 대한 이해가 필수적이다. (중략)

• Korean Journal of Materials Research
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• v.10 no.8
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• pp.564-568
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• 2000

Langmuir-Blodgett(LB) 법은 미래의 분자전자소자를 위한 가장 유력한 수단이며, 이러한 분자박막 소자는 그 성질이 분자는 배향에 영향을 박데 되므로 현재 새로운 물질을 이용하여 분자전자소자의 제작에 있어 관심을 모으고 있다. 본 연구에서는 (N-docosyl quinolinium)-TCNQ(1:2) 전하 이동 착물 LB 막의 분자 배향을 UV/vis 편광흡수 스펙트럼과 FT-IR transmission 및 reflection-absorption 스펙트럼의 흡수강도를 비교하여 정량적으로 평가하였다. 그 결과 TCNQ의 transition dipole moment의 각은 약 56~58。 였으며, 알킬 고리의 경사각은 약 11.1~13。였다. 제작된 Z-형 LB 막의 표면은 고압에서 중앙 높이 차가 3~4$\AA$으로 평탄하였다.

• Polymer(Korea)
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• v.26 no.4
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• pp.431-438
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• 2002

We studied the orientation behavior and thermal stability of polyimide (PI) molecules under irradiation of polarized UV (PUV) using polarized fourier transform infrared (FTIR) spectroscopy. In the case of PUV-exposed PI films, the remaining PI molecules after photo-degradation showed molecular orientation perpendicular to the irradiated PUV polarization direction predominantly, due to the preferential degradation of PI molecules parallel to the irradiated PUV Polarization direction. On the other hand, the rubbing of PI films induced reorientation of the PI molecules parallel to the rubbing direction. We also investigated the thermal stability of the alignment layers furled by rubbing and PUV irradiation on the PI films using Polarized FTIR. The thermal stability of the PUV irradiated PI alignment layer is lower than that of the rubbed PI layer due to the fragmentation reaction of the PI by PUV.

• Polymer(Korea)
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• v.26 no.2
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• pp.209-217
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• 2002

We studied the mechanism of orientation of polyimide molecules which were irradiated by polarized UU (PUV) using polarized Fourier transform infrared (FT-IR) spectroscopy and ultraviolet (UV) spectroscopy, According to the measured UV spectra, we found PI films mainly absorb UV light less than 350 nm wavelength, therefore, UV light less than 360 nm induces photochemical reaction of PI. PUV irradiation of PI films caused decrease of all peak intensities in the FT-IR spectra. except the newly formed broad peak at $3244 cm^{-1}$, due to degradation of the PI molecules. The remaining PI molecules after photo-degradation showed predominantly perpendicular molecular orientation to the irradiated PUV polarization direction, due to the preferential degradation of PI molecules parallel to irradiated PUV polarization direction. However the rubbing of PI films induced reorientation of the PI molecules parallel to the rubbing direction. We also investigated the alignment of the liquid crystal by rubbing or PUV irradiation. Liquid crystals align perpendicular to the PUV polarization direction and parallel to the rubbing direction.

• Journal of Satellite, Information and Communications
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• v.9 no.3
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• pp.22-26
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• 2014

This paper introduces homogeneous liquid crystal (LC) orientations on chemically modulated polystyrene (PS) surfaces using various ion beam (IB) exposure time. Transparent PS was replaced with conventional polyimde material. Especially, PS has higher transparent property than conventional polyimide thin film and it means PS is more suitable material for producing high brightness mobile LCD. As a non-contact process, IB bombardment process induced LC orientation in the direction parallel to the IB process. Through x-ray photoelectron spectroscopy, it was shown that the chemical compositional changes of the IB-irradiated PS surfaces were determined as a function of IB exposure time. Using this analysis, the optimal IB bombardment condition was determined at IB exposure time of up to 15 s. Moreover, thermal stability on IB-irradiated PS surfaces were carried out which showed that a relatively high IB exposure time induced a thermally stable LC alignment property. And it has a highly potential of mobile high transparent mobile LCD such as smart phone display and mobile information device.

• Polymer(Korea)
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• v.32 no.3
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• pp.290-294
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• 2008

Induction mechanism of molecular orientations for a rubbed polymer film as an alignment layer was investigated using polarized UV/Vis spectroscopic experiments for polyimide and polyvinylcinnamate whose conjugated electrons are located along main chain and side chain, respectively. By determining anisotropy formed in the rubbed film, LC director formed in the LC cell, and orientation direction of deposited pentacene molecules, it was found that LC orientation was induced mainly by molecular interactions whereas surface microgrooves formed by the rubbing process affect the orientation direction of deposited pentacene molecules.

• Clean Technology
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• v.28 no.3
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• pp.249-257
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• 2022

The adsorption equilibria of nitrogen on a region of nanoporous carbonaceous adsorbent with local molecular orientation (LMO) were calculated by grand canonical Monte Carlo simulation at 77.16 K. Regions of LMO of identical size were arranged on a regular lattice with uniform spacing. Microporosity was predominately introduced to the model by removing successive out-of-plane domains from the regions of LMO and tilting pores were generated by tilting the basic structure units. This pore structure is a more realistic model than slit-shaped pores for studying adsorption in nanoporous carbon adsorbents. Their porosities, surface areas, and pore size distributions according to constrained nonlinear optimization were also reported. The adsorption in slit shaped pores was also reported for reference. In the slit shaped pores, a clear hysteresis loop was observed in pores of greater than 5 times the nitrogen molecule size, and in capillary condensation and reverse condensation, evaporation occurred immediately at one pressure. In the LMO pore model, three series of local condensations at the basal slip plane, armchair slip plane and interconnected channel were observed during adsorption at pore sizes greater than about 6 times the nitrogen molecular size. In the hysteresis loop, on the other hand, evaporation occurred at one or two pressures during desorption.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10b
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• pp.207-208
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• 2003

일반적으로 결정성 고분자에 공정에 있어서 배향 및 결정화 거동은 두 가지 중요한 공정 프로세스로써 고분자의 모폴로지 및 결정구조형성에 매우 큰 영향을 미치며 최종적으로 고분자의 거시적인 물성에 영향을 준다. 고분자 물질의 물리적 특성을 정확하게 이해하여 최적의 물성을 나타내는 내부 구조를 제시하기 위하여서는 고분자 물질의 배양분석에 있어서 분자의 2차원적 배향 상태뿐만 아니라 전체적인 3차원 배향 상태에 관한 정보가 필수적이다. (중략)

• Polymer(Korea)
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• v.29 no.4
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• pp.413-417
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• 2005

Orientations of liquid crystal molecules on a surface of a film of photoreactive polyvinylcinnamate were investigated in order to apply as an alignment layer of LCD. When the polyvinylcinnamate film was exposed to linearly polarized W light, optical anisotropy was induced in the film through a selective photoreaction. Liquid crystal molecules on a surface of the film was aligned along the oriented polymer chain direction through intermolecular interactions. Thermal and light stability of the photoaligned LC cell were studied by investigating LC alignment changes after the alignment layer was treated with heat and W light. When the film was exposed with linearly polarized UV several times, the LC alignment was induced only along the final UV exposure direction.