• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.854-857
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• 2006

The synthesis of ester type, banana-shaped, photo - crosslinkable mesogens is described. The reactive mesogens, derivatives of 1,3-phenylene bis{4-[4'- (alken-1-yloxy)-biphenyl-4-carboxylate]benzoate}s, were synthesized varying the length of alkyl end groups. The obtained monomers and polymers were characterized by FT/IR, NMR spectroscopy, DSC, polarized optical microscopy, and X-ray diffractometry.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.633-636
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• 2009

New polyesters with bent-shaped mesogens were synthesized varying the central unit with 1,6- and 2,3- naphthylenes, and introducing the dodecamethylene flexible spacer. The mesogenic properties of the polymers were characterized by FT-IR spectroscopy, DSC, polarizing optical microscopy.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.762-765
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• 2004

Patterned alignment of reactive mesogens on a grating was investigated for use in phase retarders. The relative importance of the topology and the surface energy of the grating for RM alignment is discussed. Possible mechanisms of RM alignment for different grating pitches are discussed.

• Polymer(Korea)
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• v.35 no.5
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• pp.493-498
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• 2011

Reactive mesogens were used to prepare photo-cured liquid crystal films in which orientations of liquid crystal molecules were preserved by crosslinked networks of cured reactive mesogens. The molecular orientations of liquid crystal mixtures of photo-reative mesogens and non-reactive nematic liquid crystals were studied and compared before and after curing reactions. The effects of temperature and the amount of the non-reactive nematic liquid crystal in the mixture on birefringence of the liquid crystal films were investigated. It was found that optical compensation films with different birefringence could be prepared by controlling the amount of the nematic liquid crystals in the reactive mesogen mixtures.

• Journal of Information Display
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• v.5 no.2
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• pp.23-26
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• 2004

For high end, large area displays, all current LC modes require some degree of optical compensation to improve the front of screen viewing experience. Currently most optical films are laminated to the outside of the LCD cell, between the glass and polariser. In this paper we wish to show how it is possible to integrate the compensating optical film within a VA mode LCD cell. The paper will describe the process of making the biaxial film through the process of in-situ photopolymerisation of an aligned film of reactive mesogens in the cholesteric phase using polarised UV light. The film can be made on the colour filter array side of the LCD panel. In addition the process of fabricating a VA mode LCD containing this film will be described and the performance of this module will be presented.

• Bulletin of the Korean Chemical Society
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• v.23 no.9
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• pp.1201-1210
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• 2002

A new series of hyperbranched aromatic polyesters containing azoxybenzene mesogens and polymethylene spacers were prepared by polymerizing AB2 type monomers that have the isophthaloyl dicarboxylic acid terminal at one end and the p-oxyp henol terminal at the other end. The monomers contain a built-in azoxybenzene mesogen that is linked to the terminal groups through polymethylene spacers. The polyesters prepared were characterized by solution viscosity, differential scanning calorimetry, X-ray diffractometry and polarizing microscopy. All of the polyesters were found to be thermotropic (nematic). Their glass-transition temperatures and mesophase temperature ranges were very sensitive to the length of the two spacers existing in the repeating unit. The degree of branching of one of the polyesters was determined by the NMR spectroscopy and found to be 0.56.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1361-1362
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• 2009

We challenge to use reactive mesogen optical elements which can be coated inside LC cell. The reactive mesogens as retarder barrier requirements can be achieved between a high performance 2D mode and a low cross talk stereoscopic 3D mode. The fabrication of a 10.1" diagonal LCD which co-operates with a polarizer to from a parallax barrier, is described. In addition, the parallax barrier of reactive mesogens can easily control in mass production and can thus be coated as extremely LC cell, significantly reducing the thickness of LCD. Finally, we have successed to design a switchable 2D/3D displays using reactive mesogen optical elements which can be achieved 3D displays within glasses.

• Bulletin of the Korean Chemical Society
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• v.20 no.12
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• pp.1421-1427
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• 1999

4-Hydroxy-4'-methoxyazobenzene and 4-hydroxy-4'-cyanoazobenzene were synthesized from phenol with p-anisidine and p-aminobenzonitrile through a diazotization reaction, respectively. They were reacted with 2-chloroethanol, 2-(2-chloroethoxy)ethanol, or 2-[2-(2-chloroethoxy)ethoxy]ethanol to produce six kinds of new mesogenic alcohols having an azobenzene group that is sensitive to the ultraviolet. Twelve kinds of new photoresponsive monomers with two symmetrical mesogens were prepared by the reaction of the mesogenic alcohols with fumaric acid or maleic acid through a Mitsunobu reaction. The resulting monomers have different length of flexible ethyleneoxy spacer tethered to azobenzene group. The length of the spacer affected their thermal stability, solubility, and phase transition temperature. Structures of the monomers were identified by FT-IR and ¹H-NMR spectra. Their phase transition temperatures and thermal stability were also investigated by a differential scanning calorimetry (DSC) and a thermogravimetric analysis (TGA). From an optical polarizing microscopy, all the prepared monomers except fumarate-1 and maleate-1 were found to show enantiotropic liquid crystallinity with a smectic texture like focal-conic, fan-shaped, and batonnet textures.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.300-301
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• 2004

• Applied Chemistry for Engineering
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• v.9 no.1
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• pp.71-75
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• 1998

Liquid crystalline compounds with amine terminal group and related linear and cross-linked liquid crystal polymers with epoxy resin structure were synthesized and characterized to develope matrix materials for polymer dispersed liquid display applications. Both linear and crosslinked side chain type liquid crystal polymers made with aromatic amine mesogens and ethylene glycol diglycidyl ether exhibited nematic texture as shown by polarized optical microscope(POM) and their transition temperatures were determined both by DSC and POM. Liquid crystal polymer samples also showed even-odd effect as the spacer length of aromatic amine mesogens were varied, however, the effect was samller than that of low molecular weight mesogens. Changes of nematic-to-isotropic transition($T_{NI}$) of crosslinked type polymer liquid crystals were also disscussed in relation to the concentration change of crosslinking agent 1,10-diaminodecane.