Composite films of polymer and liquid crystal have been prepared by photopolymerization of a mixture of polymer precursor and liquid crystal. When the photopolymerization is performed at the nematic phase in a homeotropic cell, polymer networks are formed with an orientation parallel to the liquid crystalline director. The electro-optical properties of the films are strongly dependent on the concentration of polymer component at a large applied voltage. This result indicates that the polymer networks can reduce the liquid crystalline flow accompanying the director re-orientation.

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We noticed that molecular shape of the immunosuppressant, FTY720, is very similar to those of rod-like liquid crystals. Very interestingly, it was reported that the immunosuppressive ability depends on the chain length. Thereby, we have synthesized the immunosuppressant of 2-amino-2-[2-(4-alkylphenyl)ethyl]propane-1,3-diol hydrochloride having different length of chain, and investigated their mesomorphism. According to our expectation, they exhibit a mesophase. The mesophase was revealed to be a SA phase.

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We synthesized new chiral dopants having two trifluoromethyl asymmetric frames derived from an optically active 4,4,4-trifluoro-3-(4-methoxyphenyl)buthanoic acid. Some dihydroxy aryl compounds such as dihydroxy benzene, dihydroxy naphthalene, dihidroxy biphenyl were used as the central cores.Their central cores and chiral parts were linked by ester or ether bond. It was found that the helical twisting power (HTP) values of new chiral dopants were affected by the substituted positions of the chiral parts, the central core, and the types of linkage. The tendency of the HTP values were different between benzene core and naphthalene core.

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We synthesized new chiral dopants from (1R, 2R)-(+)-cyclohexane dicarboxylic acid anhydride. Their helical twisting power(HTP) values were evaluated in nematic liquid crystals. The magnitudes of their HTP were largely influenced by the type of linkage between the cyclohexane frame and the aryl moieties. The chiral dopant(6) having a keton and an ester linkages showed the largest HTP value(16 micrometer-1).

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We have studied the functionality of metal complexes as a chiral dopant inducing chiral nematic phases. In this report, we present an attempt of preparing a metal complex responsive to light illumination. For that purpose, a chiral Cr(III) complex with an alkyloxy derivatized 1,3-diketonate ligand was synthesized. The complex underwent photo-racemization in solution. When it was used as a chiral dopant, the helical pitch of an induced chiral nematic phase enlarged under the illumination of UV light.

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We examined the molecular weight dependence of phase transition behavior for poly(6-[4-(4'-cyanophenyl) phonoxy] hexyl acrylate) prepared by ATRP, which shows reentrant polymorphism with the variation of degree of polymerization (Dp). For the samples with moderate molecular weight (Mn 7,900~20,000) nematic, smectic A and reentrant nematic (RN) phase were exhibited whereas that with higher molecular weight only nematic phase was observed. Furthermore, the difference of dynamics in these two nematic phase has been confirmed by dynamic light scattering (DLS) measurements. The two types of nematic phase is found to be definitely distinguished each other with the two characteristics. This result is ascribed to that the increasing of dimerized mesogen acting as physically linking agents of polymer chains. On the basis of the knowledge, the direct RN-N transition is strongly suggested by DLS measurement for the samples with higher molecular weight.

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Octahomotetraoxacalix[4]arenes bearing carboxyl groups on their upper rim and long alkoxy chains on their lower rim were prepared. These compounds showed liquid crystal phases when alkylidenediamines were added. They were assembled via ionic bonds to form capsules and exhibited smectic liquid crystal phases. Further as these mixtures were heated, alkylidenediamines were vaporized out around their boiling points, yet smectic phases were still kept. According to powder X-ray diffraction analysis, the peaks corresponding to shorter layer distances were observed after their evaporation. The chain lengths of alkylidenediamines were crucial to form liquid crystal phases.

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This paper describes the properties of liquid crystals with nitro substituents at the lateral position. The layer spacings of smectic A and C phases were examined by an X-ray diffraction and compared with the molecular lengths calculated by a semi-empirical molecular orbital method. The layer spacing in smectic A phase of nitro compounds shows a linear correlation with the carbon number of the hydrocarbon chain. We proposed a new analytical method for determination of layer structure in smectic phases. Based on these results, the molecular arrangements in smectic A and C phases will be discussed.

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We synthesised new series of non-symmetric banana-shaped compounds in order to consider the influence of the alkyl terminal chain length on the banana system. These materials were found to form nematic, B1 and B2 phases depending on the chain length.

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A periodic striped pattern was observed in an anticlinic smectic C phase of a homeotropically aligned sample of a binary mixture of polar non-symmetric dimeric liquid crystals. We have investigated effects of spacer,tail and core structures of the dimeric liquid crystals on the spontaneous pattern formation. The wave pattern only appeared in the induced interdigitated SmCanti phase of binary mixtures between the dimeric liquid cystals with a different odd-numbered spacer.

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We have prepared some novel U-shaped dimeric liquid-crystalline molecules in which two phenylpyrimidine groups are connected via trans-1,2-cyclohexanediol, p-toluenesulfonamide or cis-2-butene-1,4-diol. The trans-1,2-cyclohexanediol derivative was found to show enantiotropic N and SmA phase with low melting point. On the other hand, the p-toluenesulfonamide derivative showed only a monotropic SmA phase. Furthermore, a SmC phase was found to be induced in a binary phase diagram between the trans-1,2-cyclohexanediol derivative and the cis-2-butene-1,4-diol derivative. We discuss the effect of the linking group on phase transition behavior of the U-shaped system.

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We have prepared novel U-shaped liquid-crystalline compounds where two polar mesogenic groups are connected via catechol. Phase transition behavior and electro-optical properties for the U-shaped system have been investigated and compared with those of their corresponding monomeric compounds. The U-shaped molecule, 1-{6-(4-trifluoromethylphenyloxy)hexyloxy}-2-{6-[4-(4-fluorophenyl)phenyloxy]hexyloxy}benzene, was found to induce larger dielectric anisotropy in the nematic phase of the mixture with a host liquid crystal than the corresponding monomeric polar compound.

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A novel non-symmetrical dimeric liquid crystal including two distinct mesogenic groups; 4-(4-fluorobenzoyloxy)phenyl and 4-(4-n-hexyloxybenzoyloxy)-2,3,5,6-tetrafluorophenyl, was synthesized and the mesomorphic properties were studied using a differential scanning calorimeter and a polarizing microscope. This compound exhibited an enantiotropic nematic phase. In addition, two symmetrical dimeric liquid crystals were synthesized in order to compare the mesomorphic properties of these compounds with that of the non-symmetrical one. One of them includes two 4-(4-fluorobenzoyloxy)phenyl as the mesogenic group, and the other has two4-(4-n-hexyloxybenzoyloxy)-2,3,5,6-tetrafluorophenyl. The effects of substitution of fluorine atoms and the symmetry of the molecules are discussed in detail.

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6/7-Membered ring systems with a methacryloyloxyalkoxy benzoate and their polymers were synthesized. The thermal behavior of the monomers and the polymers has been characterized using polarized light microscopy and differential scanning calorimetry. Monomers showed nematic phase and smectic A (SmA) phase and polymers showed SmA phase whereas troponoid polymers with a long alkoxy side chain exhibited SmA phases. The liquid crystalline phases were significantly affected by the length of the spacer and the alkoxy side chain. The number-average molecular weights (Mn) were determined by GPC using polystyrenes as standards. The Mn and the molecular weight distribution (Mw/Mn) of each polymer were described.

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Rod like 1,2,5-thiadiazole ring condensed terphenyl derivatives 1-3 with a cyano and a long alkoxy group were synthesized. All compounds exhibited strong fluorescence and liquid crystalline phases. Strong fluorescence was observed in crystalline state, mesophase and isotropic phase of all compounds. It was found that the emission wavelength and the phase transition behaviors of 1-3 were affected by the position of the condensed 1,2,5-thiadiazole ring in the terphenyl skeleton.

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Polysilacage compounds, 1-alkyl-4-phenyl-2,3,5,6,7,8-hexasilabicyclo[2.2.2]octanes, exhibit hexagonal columnar and rectangular columnar phases in spite of the rod-like molecular structures. To stabilize the mesophases, we introduced a cyano group at the para-position of the phenyl group. Optical measurement disclosed that hexagonal columnar and rectangular columnar phases appeared with alkyl groups ranging from methyl to hexyl, while lamellar columnar phase was observed with a heptyl substituent. Comparison of the mesogenic behavior with parent non-cyanated compounds indicates that the cyano group remarkably enhances the structural order of the mesophase.

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Rod-like liquid crystalline compounds 1 and 2 possessing an pyridine ring at the central flexible spacer connecting two mesogens were synthesized and their thermodynamic behaviors and layer structures were investigated. Bent-rod shaped molecules 1 exhibited monotropic mesophases (M). On the other hand, straight-rod shaped molecules 2 exhibited highly ordered smectic phases (SmX1 and SmX2). Additionally a miscibility experiment of 1 and phenylbenzoate derivative 3 was performed to investigate the dopant effect of the bent-rod shaped molecule to conventional smectic C phases. A monotropic smectic CA phase was induced, which was identified by polarized optical microscopy.

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We prepared 4-(4'-octyloxy)biphenyl p-nitrobenzoate (8OBNB) as a liquid crystalline molecule bearing a strong electron acceptor. The absorption spectra of 8OBNB and its model compounds were measured to evaluate the intra- and intermolecular charge-transfer characteristics of 8OBNB. 8OBNB showed smectic A phase in a wide temperature range. In addition to a weak intramolecular charge-transfer interaction of 8OBNB, a marked intermolecular charge-transfer absorption was observed between 8OBNB and N-phenyldiethanolamine as an electron donor. The polarization dependence of the absorption of 8OBNB in alingned cells was also measured and discussed.

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Oligopeptides derivatives containing lipophilic amino acids are designed and synthesized for the development of new hydrogen-bonded liquid crystals. These oligopeptides derivatives show thermotropic hexagonal columnar phases. The isotropization temperatures of the columnar phases become higher as the number of the amino acid moieties increases. The FT-IR and X-ray scattering measurements of the materials show the formation of intermolecular hydrogen bonds of the oligopeptides along the column axis.

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The relationship between structure of liquid crystals and molecules was studied on 1,4-dibenzyloxybenzene and a benzoic acid derivative using X-ray measurements.The molecular length of 4-dodecyloxybenzoic acid dimer by X-ray structure analysis is 37.5 Å and the obtained tilt angle is 37.6 ºfor the SmC phase at 378 K.

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This paper describes the synthesis and properties of liquid crystals incorporating a chromen-2-one skeleton at the terminal position, and a 2H-pyran-2-one for the comparative study. The 4-alkoxybenzoate and 4-alkoxybiphenyl-4'-carboxylate esters tend to exhibit smectic A phase, probably due to polar interactions between lactone groups. Based on these results, the molecular arrangement in smectic A phase will be discussed.

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This paper describes synthesis and properties of liquid crystals incorporating a 1,3-benzoxathiol-2-one skeleton at the terminal position. The 4-alkoxybenzoate and 4-alkoxybiphenyl-4'-carboxylate esters tend to exhibit smectic A phase as well as nematic one. The layer structure of the SmA phase was characterized by a small angle X-ray diffraction method, and discussed in terms of the molecular properties estimated by a semi-empirical molecular orbital calculation.

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Oxadiazole derivatives are well known as electron transport materials. Five novel 1,3,4-oxadiazole derivatives were synthesized from 2,5-bisalkoxyterephtalic dihydrazide and p-alkoxybenzoyl chloride, and their derivatives were soluble in chloroform. Thermal properties and UV –vis spectra of oxadiazole derivatives are dependent on the number of carbon atoms in the terminal alkoxy group. As the number of carbon atoms increased, the blue shift of the peak assigned to the oxadiazole ring was observed in the UV-vis spectra. Photoluminescence spectra of oxadiazole derivatives were independent on the terminal alkoxy group.

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A series of 3b-alkoxy-5a-cholestan(ACA, n=3-8) was prepared and their mesogenicity was studied using POM observation, DSC and X-ray diffraction measurements. The existence of a monotropic cholesteric phase was suggested in n=7.

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Side chain liquid crystalline polymers have been expected to be used as electrorheological (ER) fluids, because the orientation of the side chain terminal groups may easily occur under an applied electric field. In this study, a side chain liquid crystalline polysiloxane derivative including mesogens with cyano group and fluorine atom in the side chain was prepared because it was considered that an appearance of the ER effect was dependent on a positive dielectric anisotropy of the side chain terminal groups. A phase transition behavior and ER effect of the compound will be discussed.

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Novel surface profiler system for inspection of the display components is demonstrated. In the case of the liquid crystal display, for example, not only the flatness of the alignment film but also the quality of rubbing can be inspected. This instrument is applicable for EL glass substrate as well as LCD and PDP. To visualize the shape of the back plane, no preparatory treatment (viz. remove the alignment film) is required. That is, in-line panel inspection of the real product can be realized.

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We have investigated an alignment of nematic liquid crystal (NLC) molecules using nanometer-sized ultra-fine groove, tilt, and dot patterns fabricated by electron beam exposure method. In order to improve a wetting condition of NLCs, we sputtered silicon di-oxide on a substrate after fabrication of ultra-fine patterns. For a homogeneous alignment cell with ultra-fine groove pattern, azimuthal anchoring energy of 2.48*10^-4 J/m^2 was obtained. We also confirmed tilt and homeotropic alignment using tilted and dot patterns, respectively.

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A reflective color LCD of high quality, low power consumption, light weight and thin structure is an important device for highly portable information terminals. In this report, we numerically analyzed the influence of the material parameters on the electro-optical properties in various types of a single-polarizer reflective TN-LCD in order to confirm the possibility of reducing power consumption. Our results demonstrate that ultra-low-power (1V in the on-state) reflective TFT-LCDs with high-quality images can be realized if a liquid-crystal material with a small value of K11 and a large value of Δ ε can be developed.

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Recently, with use expansion of LCD application, the requirement of high reliability for LCDs is more and more ncreasing. Since image sticking, one of the reliability of LCDs, could be estimated by measuring the residual DC voltage of LCDs RDC), we investigated the RDC by changing thickness of the alignment layers and the electrode materials. We found hat the RDC value is minimized at certain thickness of alignment layer (around 200A), and the RDC is strongly influenced by the electrode under the alignment layer.

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In order to realize the wide-viewing-angle liquid crystal displays (LCDs), the design and the evaluation of an optical compensation film has been important. The conventional design parameter has a problem that the viewing angle characteristics of the retardation film depend on film materials. In this research, we have theoretically analyzed the relation between three dimensional refractive indices and viewing angle characteristics of biaxial films, and we defined the design parameter Tz of the retardation film without depending on the refractive index of materials.

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For the Bi-Nem LCD, the optimization for the arrangements of the LC cell, the polarizer and the analyzer has been investigated in order to obtain the optical high contrast ratio (CR). Furthermore, the computer simulation has been done, based on the Raynes's optical model in the twisted nematic LC cell. Experimental results have been compared with the simulated results. In the computer simulation, the best CR was obtained at the condition (Fa,Fi) = (65[deg.], 30[deg.]), where Fa is the angle between the polarizer and the analyzer, and Fi is the angle between the polarizer and the input director. The good agreement between them for Fa and Fi has been obtained.

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Dichroic fluorescent dyes are dissolved into homogeneous, 90deg twisted-nematic(TN) and homeotopic liquid crystal cells. Intensities of the polarized fluorescence excited by the polarized UV light are measured in three types of LC cells and their electro-optical properties are measured. The steepness and the contrast ratio of the LC cell are also estimated.

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The stopping action for the four terminal LC cell is studied. The TN cell is improved in the aperture rate, boundary sharpness and response time by the novel dual frequency overlapping method using the dual frequency driving liquid crystal. The sharp boundary is caused by the forced arrangement of LC molecules , either homogeneous or heterogenoeous state, in any position of the cell.

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We have directly observed the flow of nematic liquid crystal droplets between glass plates on the assembling process. The droplet concentrically expanded at slow speed on the initial stage and then expanded at high speed in proportion to the assemble rate. The two-step fluid was observed irrespective of different rubbing strength of PI alignment film. The shape and flow properties of liquid crystal droplets depended on the rubbing strength. The diameter of the droplet increased with rubbing strength during the assembling process.

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In order to realize flexible displays, we fabricated an A4-sized ferroelectric liquid crystal (FLC) display device using microcolor filters mounted on a plastic substrate. The color filters and ITO electrodes were formed on a glass substrate, and then transferred to the plastic substrates. This technique can form flat surface of the substrate and make fine patterning of the color filters and ITO electrodes. Then, an FLC/monomer solution film was uniformly coated on the substrate by flexographic printing method to form a large-size FLC/polymer composite film sustaining the plastic substrates. A fabricated A4-sized device with color pixels presented images even when the device was bent.

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Poly(propyleneimine) dendrimers having peripherally mesogenic groups(LCDs) exhibited a smectic liquid crystalline nature. When they were slowly cooled from the isotropic melt, a homeotropic structure was spontaneously formed on a glass plate in smectic A phase. The homeotropic structure was observed in LCD/5CB blend systems in this study. Using LCD having peripherally cianobiphenyl mesogen, it could be formed in the 0.1wt%-LCD blend exhibiting nematic phase. It suggests that the LCD induced to stand 5CB molecule vertically on a glass plate. LCD with azobenzen mesogen also exhibited a homeotropic alignment in LCD/5CB blend systems.

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In this study, we have synthesized liquid crystalline telomers and investigated their properties. The molecular weights of the telomers have been found to decrease with the increase of telogen content. Isotropization temperatures of the telomers from liquid crystalline to isotropic phase are determined as a measure of the stability of the telomers which shows that stability depends on its molecular weight and structure of the telogen.

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Thermal and photochemical properties of polyethylene imine (PEI) having side chains with azo dye unit (4'-butylazobene derivative) were investigated. We synthesized two PEIs having different spacer length between the main chain and the azo dye unit. PEI104 having longer methylene spacer was found to form an out-of-plane structure by heating up to an isotropic phase and following cooling. The photochemical control of the molecular orientation of PEI104 between in-plane and the out-of-plane structures was achieved by a combination of thermal and photochemical processes.

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Polarization holograms have been recorded in azo-dye-doped liquid crystal composites by using the two coherent laser beams with orthogonal polarization. The mesogenic composites consist of the azobenzene dye, low-molar-mass liquid crystalline mixture, and side chain liquid crystal polymer. All components were miscible and were homogeneously aligned in the single phase. The experimental results and theoretical analysis indicate that both liner and circular birefringence was induced in the composite films.

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Photoorientation of Polymethacrylate copolymer liquid crystal film substituted with 4-methoxyazobenzene and 4-methoxycinnamoyloxybiphenyl side groups using linearly polarized (LP) He-Ne laser is described. High-order in-plane molecular orientation both azobenzene and cinnamoyl groups parallel to polarization (E) of LP 633 nm light was generated by irradiating with non polarized 365 nm light and LP 633 nm light and subsequent annealing.

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Electrical tuning of the light diffraction has been demonstrated in the periodic structure infiltrated with nematic liquid crystal.The one- and two-dimensional periodic structures have been fabricated by means of holographic lithography using interference beams of pulsed laser.The diffraction efficiency of the liquid crystal infiltrated grating could be controlled upon applying electric field.

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A photonic crystal has a structure with a periodicity equivalent to optical wavelength. In particular, the study of a defect mode in photonic band gap is one of the most attractive subjects. A one-dimensional photonic crystal with conducting polymer and nematic liquid crystal as a defect layer has been studied. Upon applying electric field, the defect mode wavelength in the photonic band gap can be controlled by the reorientation of the liquid crystal molecules. Furthermore laser action at the localized state in the band gap has been observed, and the lasing wavelength was controlled upon applying the electric field.

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We have adopted the finite domain time difference (FDTD) method to analyze the electro-magnetic field distribution of light propagating through a choleresteric liquid crystal (CLC) layer. FDTD calculation is a method used widely in the area of telecommunication to investigate electro-magnetic (EM) field distribution, and is based on solving the Maxwell Equation numerically by converting differentiations to simple differences over a small discrete period of time and distance. We have demonstrated the electric field distribution of selective reflection of light as well as a standing wave occurring at the band-edge wavelength of a CLC medium. It has been confirmed that FDTD calculation is a powerful tool for investigating the EM field distribution upon time and space propagation.

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We form polymer walls in liquid crystal (LC) layer using thermal phase separation of an LC/polymer solution between substrates with patterned polyimide films. The difference of wetting between the polyimide film and the substrate surface causes the coalescence of the LC droplets on the polyimide films in the phase separation. Consequently the polymer walls are obtained on the substrates. Additionally, the walls become sharp by using rubbed polyimide films because the nucleation of the growing LC droplets concentrates on the polyimide films. It is thought that the increase of the LC alignment order in the solution near the rubbed polyimide films promotes the LC molecular aggregation which becomes the growth nuclei of the LC droplets.

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Using the rotating photo alignment method, various orientation patterns with a point symmetry with respect to the rotation axis were experimentally depending on the direction of sector slit in the photo mask and the polarization direction of the UV light. In this report, by computer simulations we try to reproduce the orientation pattern obtained by the rotating photo alignment method.

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Liquid crystal (LC) anamorphic lens is reported. The lens is realized by using an LC cell with a transparent electrode and a hole-patterned electrode divided into eight parts. By applying appropriate potentials on each part of the electrode, the LC cell behaves like an anamorphic lens. An incident plane light wave experiences a nearly elliptical profile of phase shift. The applied voltages can rotate the two axes of the elliptical profile and change the ratio of the two axes.

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A two-layer liquid crystal (LC) lens using a new electrode structures proposed recently are reported. A driven method is employed and no disclination lines appearing in the LC layer. The thickness of the LC layers in the cell is much thinner than those used before. The response time of the LC lens can then be controlled within 1 second. With the new technique it becomes possible to build an LC lens with multi-LC layer, and a responsive LC lens with desired focus power can be realized.

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A liquid crystal lens with spherical electrode is numerically studied. When the spherical electrode closes to the liquid crystal layer, or a spherical electrode of a smaller radius of curvature is used, a large focus power can be obtained. With a larger radius of curvature or a thicker glass substrate that is between the liquid crystal layer and the spherical electrode, the liquid crystal lens exhibits better quality in a larger voltage range, and it is not easy for disclination lines to occur.

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An experiment of the Photo electromotive force (P. e. m. f.) of Nematic Liquid Crystal cells were performed on the irradiation of various light sources and the temperature characteristic of cells. The fabricated cells were mixed dyestuffs that are 3% weight ratio of Liquid Crystal. The light sources used for the experiment are a daylight fluorescent lamp, the white LED, the blue LED, the laser diode, infrared rays LED and an incandescence electric bulb. The temperature characteristic of cells were measured on the P. e. m. f. changing the temperature at intervals of 5 CEL between 10 and 60 CEL. The cell mixed Alizarin Yellow generated the highest P. e. m. f. in 50 CEL.

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An electric field sensor utilizing a ferroelectric liquid crystal is proposed in this study. Since the ferroelectric liquid crystal has spontaneous polarization, the response sensitivity to an applied electric field is relatively high. A trial practicable electric field sensor utilizing these features are produced and evaluated.

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