• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.1112-1117
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• 2003

Polarized Fourier transform infrared (IR) absorption is used to probe molecular conformation in a ferroelectric liquid crystal (FLC) during the reorientation induced by the external field. Spectra of planar aligned cells of FLC W314 are measured as functions of IR polarizer orientation and electric field applied to the FLC. The time evolution of the dichroism of the absorbance due to biphenyl core and alkyl tail molecular vibration modes, is observed. Static IR dichroism experiments show a W314 dichroism structure in which the principal axis of dielectric tensor from molecular core vibration are tilted further from the smectic layer normal than those of the tail. This structure indicates the effective binding site in which the molecules are confined in the Sm-C phase has, on average, "zig-zag" shape and this zig-zag binding site structure is rigidly maintained while the molecular axis rotates about the layer normal during field-induced switching.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1993.05a
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• pp.55-58
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• 1993

In this paper, the relationship between trap properties and the molecular orientation owing to elongation was investigation from TSC, electrical conductivity and X-ray diffraction was investgated. The changes of the stretching direction, from an a-axis orientation(at low elongation) to a c-axis orientation(at high elongation), as the elongation increases. were determined from X-my diffraction patterns. These results suggest that the tendency for a decrease in the trap density at a higher elongation is consistent with a continuous change of the reorientation from the a-axis to the c-axis as the elongation increases.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.05
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• pp.123-125
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• 1996

The orientation effect of galactose ligand on hepatocyte attachment was investigated. Poly(N-p-vinyl benzyl-o-${\beta}$-D-galactopyranosyl-D-gluconamide) (PVLA), a ${\beta}$-galactose-carrying styrene homo-polymer, was used as a model ligand for the asialoglycoprotein receptors on hepatocytes. PYVA was transferred onto the poly(${\gamma}$-benzyl L-glutamate)(PBLG) or PBLG/ poly(ethylene glycol)(PEG)/PBLG Langmuir-Blodgett (LB) films as the monolayer level. The dichroic fluorescence values of confocal microscope indicated that the PVLA transferred onto the LB films was located with a preferential orientation of its molecular axes with regard to the direction of the a-helix of polypeptide. Hepatocyte recognized well-oriented galactose moieties of the surface of PVLA through asialoglycoprotein receptors.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.1209-1211
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• 1993

In this paper, the relationship between electrical breakdown properties and the molecular orientation owing to elongation was investigation from electrical conductivity, electrical breakdown strength and X-ray diffraction wag investigated. The changes of the stretching direction, from an a-axis orientation(at high elongation) to a c-axis orientation(at high elongation), as the elongation increases, were determined from X-ray diffraction patterns. These results suggest that the tendency for a decrease in the trap density at a higher elongation is consistent with a continuous change of the reorientation from the a-axis to the c-axis as the elongation increases.

• The Korean Journal of Rheology
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• v.10 no.2
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• pp.98-105
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• 1998

가공공정중 변형을 수반하게 되는 고분자제품은 대부분 고분자사슬의 배향을 갖게 된다. 이렇나 사슬배향은 제품의 기계적, 광학적, 그리고 전기적 특성에 매우 중요한 영향을 미치는 것으로 알려져있다. 지금까지 고분자사슬의 배향상태를 나타내기 위한 여러방법은 모두 배향의 중심축을이 알려져 있다는 가정하에 전개되었다, 그러나 복잡한 배향모드를 갖 는 고분자가공의 경우에 배향중심측이 실험축과 일치하지 않는 경우가 많다 따라서 본연구 에서는 일반적인 고분자의배향상태를 나타내는 방법에 대해 알아보고 실제 고분자 가공공정 에 적용을 위해 실험적으로 배향의 대칭축을 찾을 수 있는 접근방법을 제시하고자 하였다. 그 결과 결정성 고분자의 배향상태를 광각 x-선 회절 data를 이용한2차배향 tensor를 통해 배향 타원체를 구성할수있었다. 이를PETdustls 필름과 HDPE사출성형물에 적용해 본 결과 이들의 2차 배향 tensor가 타원체를 잘 구성함을 알수 있었다. 또한 주어진 고분자의 결정 면들에 관계없이 고유한 중심축을 지니고 있음을 확인할수 있었다. 이를 통해 복잡한 배향 모드를 갖는 경우에 본연구에서 제안한 x-타원체를 통해 결정의 배향중심축을 효과적으로 찾을수 있음을 알수 있었다.

• Textile Coloration and Finishing
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• v.4 no.1
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• pp.26-29
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• 1992

Ternary solutions that cellulose triacetate (CTA) and polyethylene terephthate (PET) were mixed in a solvent trifiuoroacetic acid (TFA)/methylene chloride (MC) (6/4 : v/v) showed phase separation and mesophase formation. The ternary systems which were mesomorphic were spun into a methanol both and relatively strong cellulosic fillaments were successfully produced. Analysis showed that CTA/PET fibers have fibrillar structure and high orientation parallel to the fiber axis. These fibers proved to be molecular composite and have relatively high strength and modulus as spun.

• Journal of Photoscience
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• v.1 no.1
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• pp.53-59
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• 1994

Molecular orientation and polarity of solubilization site of dipolar azobenzenes solubilized in micellar solutions are discussed. The polarity of solubilization was estimated by using Taft $\pi$$^*$ scale with linear solvation energy relationship, $\Delta$E=$\Delta$E$_0$ + S($\pi$$^*$ + d$\delta$)+a$\alpha$ + b$\beta$. Hydrogen bonding effects were taken into account for the estimation of micropolarity. The polarity that azobenzenes experienced in the miceliar solutions was close to water which represented that the azobenzenes were mostly solubilized at the interface. For the orientations of azobenzenes were concerned, the nitro group of NPNOH faced the interface and the hydroxy group of NPNO$^-$ located at the interfacial area.

• Journal of Korean Vacuum Science & Technology
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• v.6 no.1
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• pp.1-4
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• 2002

A simple method for real-time monitoring the molecular orientation in a polymeric film was suggested. This method was examined in the polarization holograms by two recording beams on a poly(malonic ester) containing disperse red 1. The spatial distributions of the photo-induced alignment were measured and analyzed at various polarization states of two recording beams. As the result, the directions of molecular alignments could be identified easily by our method.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.04a
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• pp.277-280
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• 1997

It is important to investigate the molecular arrangement and the orientational distribution in the study of LB films. Polarized UV/visible absorption spectra make it possible to reveal the molecular arrangement and the orientational distribution. It is clarified that the PAAS LB films have specific directions in the molecular arrangement and the orientational distribution, which art different in intensity corresponding to the surface pressure. Unpolarized UV/visible absorption spectra reveal that the surface pressure is proportional to the finn thickness and is related to the molecular orientation. Current-Voltage(I-V) measurements provide that the current decreases as the surface pressure increases and there are certain phenomena called switching phenomena. Switching effort indicates that the current flows in high conductivity during on-state and suddenly decreases into low conductivity during off-state.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.05a
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• pp.244-247
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• 1996

We had experiment using LB method that can fabricate molecular order ultra-thin film below 100${\AA}$. LB method has known as main technology of information society in 21C, because it is not only free orientation and alignment of molecular but also ability of thickness control as molecular order. In this paper, the fabricated condition and physical properties of functional ultra-thin film of molecular order was investigated and highly efficient ultra-thin film capacitor was fabricated by using ultra-thin LB film for application as electronic device. Possibility of ultra-thin film capacitor was researched by analyzing and measuring electrical properties. Polyimide ultra-thin LB film capacitor was fabricated, ensured theoretically and experimentally its possibility in range of 10Hz∼lMHz through its frequency characteristics.