• Bulletin of the Korean Chemical Society
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• 제29권6호
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• pp.1205-1210
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• 2008

A new and efficient synthetic approach is reported for biologically interesting prenylated chalcones, 4'-Omethylxanthohumol (3), xanthohumol E (4), and sericone (5) from 2,4,6-trihydroxyacetophenone. The strategies involve the introduction of a prenyl group onto an aryl ring, benzopyran formation, and basecatalyzed aldol reactions.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.489-492
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• 2003

Photoalignment materials of PGMAcr, poly[3-(acryloyloxy)-2-hydroxypropyl methacrylate] using an acrylate unit photopolymerized by a photo-initiator and PGMA4Ch, poly[3- (4-ehalconyloxy)-2-hydroxypropyl methacrylate] using photodimerization by the chalcone group were synthesized. Also, the liquid crystal (LC) alignment capabilities on the photopolymer layers were studied. A good LC alignment with UV exposure on the PGMAcr surface can be obtained. However, LC alignment defects were observed on the PGMA4Ch surface. The LC alignment capability of the PGMAcr surface by the photoinitiator was better than that of the PGMA4Ch surface by the chalcone group which is a photosensitive moiety.

• 한국전기전자재료학회논문지
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• 제14권7호
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• pp.600-605
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• 2001

The electro-optical (EO) performances for the twisted-nematic (TN)-liquid crystal display (LCD) photo-aligned with polarized UV exposure on various blending photopolymer surfaces were investigated. Excellent LC alignment and voltage-transmittance (V-T) characteristics for TN-LCD photo-aligned with polarized UV exposure of normal incidence on the blending photopolymer (polyimide (PI) +PM4Ch(poly(4-methacryloyloxy chalcone))) surface containing chalcone group can be achieved. The EO performances for the TN-LCD photo-aligned on the blending photopolymer can be improved due to the photosensitivity by long side chain of the photopolymer.

• 한국전기전자재료학회논문지
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• 제14권7호
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• pp.595-599
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• 2001

The mechanisms of pretilt angle generation for a nematic liquid cystal (NLC) using a photodimerization method with obliquely polarized UV exposure on the various new photo-crosslinkable polymer were studied. A good thermal stability of all the photo-crosslinkable polymers was obtained by thermogravimetric analysis (TGA) measurement until 450$\^{C}$. High pretilt angle of the NLC was observed by polarized UV exposure on the three kinds of the photo-crosslinkable polymers containing biphenyl(BP), decyl(de), and cholesteryl(chol) group, respectively. However, the low pretilt angle of the NLC was measured by obliquely polarized UV exposure on the two kinds of the photo-crosslinkable polymers containing fluorine and chalcone group. Consequently, the high NLC angle generated is attributable to the biphenyl and alkyl moieties, and photo-dimerized chalcone group of the photopolymer.

• 한국전기전자재료학회논문지
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• 제13권9호
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• pp.770-775
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• 2000

A new photo-polymer material of the copoly (PM4Ch-ChMA), copoly (poly (4-methacryloyloxy)chalcone-cholesteryl methacrylate) for homeotropic alignment was synthesized and the electro-optical (EO) performance for the photo-aligned vertical-aligned (VA)-LC display (LCD) was studied. Good thermal stabilities of synthesized copolymer were obtained by TGA(Thermogravimetric Analysis) measurement. Good voltage-transmittance (V-T) and response time characteristics for the photo-aligned VA-LCD with polarized UV exposure in oblique direction($\theta$$_{i}$=30$^{\circ}$) on a copolymer-1 (2%) surfaces for 1 min were observed. but, light leakage in the off-state was observed. Therefore, we achieved excellent V-T and response time characteristics for the photo-aligned VA-LCD with UV exposure on a copolymer-3 (30%) surfaces for 3 min.n.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2000년도 제1회 학술대회 논문집
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• pp.197-198
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• 2000

A surface-assisted photo-control of the liquid crystal (LC) alignment has been achieved by modifying the topmost surface of the polyimide film with photo-reactive molecules. Recently, photo-alignment technique using a thin film of poly(vinyl cinnamates) have been reported. However their commercial potentiality is limited by their low thermal stability. To enhance thermal stability, we synthesized the chalcone derivatives as the photo-reactive molecules and introduced the materials on the surface-modified polyimide film.. We identified that the photo-chemical reaction of the chalcone derivatives occur in few minutes with irradiation of UV light. The photo-alignment characteristics of the modified polyimide films treated by polarized UV light and their LC cells are investigated as a function of exposure dose.

• 한국전기전자재료학회논문지
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• 제16권11호
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• pp.1014-1018
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• 2003

A photoalignment material of a PGMAcr, poly[3-(acryloyloxy)-2-hydroxypropyl methacrylate] using a photopolymerized the acrylate unit by photo-initiator and a PGMA4Ch, poly[3(4-chalconyloxy)-2-hydroxypropyl methacrylate] using a photodimerization by chalcone group were synthesized. Also, the liquid crystal (LC) aligning capabilities on the photopolymer layers were studied. A good LC alignment with UV exposure on the PGMAcr surface can be obtained. However, the LC alignment defects were observed on the PGMA4Ch surface. The LC aligning capabilities of the PGMAcr surface by photo-initiator were better than that of the PGMA4Ch surface by chalcone group as photosensitive moiety.

• Bulletin of the Korean Chemical Society
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• 제34권4호
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• pp.1023-1024
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• 2013

• Bulletin of the Korean Chemical Society
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• 제32권1호
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• pp.65-70
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• 2011

Coumarins are ubiquitous in plant kingdom and have been used as antitumor, antifungals, anticoagulants, insecticides. Chalcones are also widespread in plant kingdom and have been known to possess diverse biological activities; antibacterial, antifungal, antitumor and anti-inflammatory, etc. As they are considered as important natural products, numerous synthetic approaches have been reported up to the present. We devise a new selective method of preparing dihydrocoumarins and chalcones from aryl cinnamates by the selection of reagents. Dihydrocoumarin derivatives were prepared selectively by using intramolecular cyclization catalyzed by p-toluene sulfonic acid. Also, chalcones were prepared by Fries-rearrangement catalyzed by $TiCl_4$. This method can be used for preparing various coumarin & chalcone compounds.

• Journal of the Optical Society of Korea
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• 제5권1호
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• pp.16-19
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• 2001

A photopolymer, copoly (M4Ch-ChMA), copoly ((4-methacryloyloxy) chalcone-cholesteryl methacrylate), was synthesized in this study. The electro-optical (EO) characteristics for the photo-aligned vertical-alignment (VA)-liquid crystal display (LCD) were investigated. Excellent voltage-transmittance curves for the VA-LCD photo-aligned by polarized UV exposure on the copoly (M4Ch-ChMA) surface were observed. The response time for the photo-aligned VA-LCD decrease with increasing UV exposure time. consequently, the photo-dimerized chalcone moiety increased with increasing UV exposure time, which then contributed to a low response time for the VA-LCD photo-aligned.