Discussed herein is the design, synthesis and structural properties of novel materials like ferroelectric, antiferroelectric, nematic, and photoresponsive liquid crystals in addition to LCs containing a hexasilabicyclo[2.2.2]octane mesogen which favors formation of a columnar hexagonal phases.

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TFT-LCD displays are attracting attention as energy-saving and eco-friendly products ontop of wide application under growing markets of flat panel TVs and mobile products.In this environment, TFT-LCDs are required for further innovations as very key devices.Therefore, we are continuously developing leading-edge technologies which createnext-generation application to meet these wants.It will introduce the vision of applied market created by the technology that can do bythese approaches.

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Synthesis of oligothiophene derivatives exhibiting chiral nematic phase will be reported, as well as their carrier transport properties.

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We have investigated charge carrier transport in the smectic mesophases of dialky 2-phenylnaphthalene derivatives. Some of the dialkyl derivatives exhibited highly ordered mesophases at ambient temperatures or lower. We could get non-dispersive transient photocurrents upon a pulse illumination from an excimer laser (wave length =308nm).
The carrier mobility of 8-PNP-4 in the smectic B phase was 6x10^-3cm²/Vs, and 3x10^-2cm²/Vs in the smectic E phase. These were three to four times larger than those in alkyl-alkoxy derivatives.
The carrier mobility depended on neither electric field nor temperature in a wide temperature range of -24 to 80^oC.

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It is surely required to develop a novel technology for the alignment control of molecular materials in order to utilize their anisotropic properties. In particular, this makes a important sense for liquid crystals and thus, it seems that the difficulty of the alignment control have given a certain disadvantage to the reserach and development for the application. The more highly viscous and ordered mesophases such as liquid crystalline semiconductors needs a novel and trustful technique for the alignment control, while the less viscous and ordered ones have been utilized successfully to the practical applications by the sustrate surface modification as well as the external fields. In this talk, a possible technique for the molecular alignment control of the highly ordered liquid crystals, polarized infrared technique, is shown and the recent results indicate this may lead to a novel fabrication technology for the diverse polymer-based devices.

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The carrier mobility of highly ordered smectic mesophases was evaluated by Time-of-Flight (TOF) method for mesogenic 1,4-di(5'-octyl-2'-thienyl)benzene (8-TPT-8) and reveal to shows the fastest drift mobility (0.1 cm²/Vs for the lowest temperature mesophase) in calamitic liquid crystals reported to date.

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The current voltage characteristics of a liquid-crystalline semiconductor 2-(4-Octyphenyl)-6-dodecyloxynaphthalene (8-PNP-O12) with various electrodes was measured and analyzed to study the hole injection from the electrodes to 8-PNP-O12. It was found that the hole injection was depressed by the dipoles formed between electrodes and 8-PNP-O12 when they were in contact with each other. The modification of the surface of an Au electrode with a dipolar self-assembled monolayer of 4-nitrophenylthiolate could significantly enhance the hole injection.

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We have investigated the molecular orientation of the polyfluorene (PFO) layers (~30 nm thick) formed on photo-aligned polyimide films. The uniaxially-aligned crystalline and glassy PFO layers were obtained by slow-cooling and quenching, respectively, of the sample from the liquid crystalline phase of PFO. For the crystalline PFO layer, an extremely high polarization ratio was observed in photoluminescence (PL), which was about 30. Such a high PL polarization ratio has not previously been reported. For the glassy PFO layer, the PL polarization ratio was 10.8. It was slightly larger than that of the glassy PFO layer formed on a rubbed polyimide film (9.5). From these results we conclude that the photo-aligned polyimide film is an excellent alignment film for PFO layers, especially for crystalline layers.

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We could control the morphology and alignment of pentacene single crystals which were segregated in liquid crystal solvent cells. We fabricated several cells with different alignment layers and thickness and grew pentacene single crystals in the cells. In addition, we tried crystal growth under applied voltage. As a result, we could change the morphology. We also studied the molecular alignment of pentacene single crystal using Raman-scattering spectral microscopy.

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The various expectations for Electronic Paper were summarized as readability, compactness, multi-functionality and less-resource. Paper-like readability should be regarded as the most urgent target for Electronic Paper, when we consider the present absence of an electronic medium that provides comfortable reading. However, it is not clear how we should pursue readability. This paper focus on how to achieve readability. Various experiments on readability have shown that not only performances of screen itself but total reading conditions, for instance handling condition of medium, should be regarded to condtion the readability.

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A novel adhesive patterned spacers technology has been developed to improve the durability against external forces and cell gap uniformity of a LCD panel. The feature of this technology is that the patterned spacers formed in various parts of the panel are adhered to the both substrates. This has been realized by putting a thin layer of resin on the top surface of the spacers. By applying this technology, a bistable FLC (SSFLC) panel with film substrates has been realized.

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In OCB type LCDs, a high voltage application is necessary to make transform the initial splay orientation to the bend orientation at the initial operation. In this study, It is theoretically and experimentally clarified that no voltage application as mentioned above is achieved by using polymer stabilization method. It is shown that the bend orientation is perfectly stabilized by the application of high frequency voltage (higher than 100kHz ) during the polymer stabilization process.

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Microcapsulated cholesteric liquid crystals (LCs) as a core material are widely utilized as key parts for LC thermometers and temperature sensitive printing. However, it does not seem to examine still very much application of the microcapsule which wraps nematic LCs as a core material. In this paper, several fundamental properties of encapsulated nematic LC (ENLC) materials are studied. Next, the possibility of utilizing this system for display and optical elements, is also examined.

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A flexible full-color moving-image display has been fabricated using a plastic-substrate-based monostable ferroelectric liquid crystal (FLC) containing polymers and a bendable backlight sheet with three-primary-color LED chip array. The threshold voltage of polymer-stabilized FLC was reduced by decreasing size and density of polymer fiber networks. The fabricated A4-sized FLC matrix panel with 96x64 image pixels was combined with the backlight sheet with a light diffusing film, and driven using outer switch transistor array based on a field sequential color technique.

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Organic-inorganic hybrid thermotropic liquid crystal has been obtained by the hybridization of an organic amine with a mesogenic core and monodispersed TiO2 nanoparticles with different sizes and shapes. It was revealed that the monodispersity played a key role for the induction of the liquid crystallinity. The nanolevel hybrid structures of the organic-inorganic hybrid liquid crystalline phases were examined by rheological measurements and small angle X-ray measurements.

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Monodispersed hematite fine particles with spindle, cuboidal, and platelet shapes have been prepared by the Gel-Sol method, which is a particle synthesis technique in condensed system. Hybridization of the monodispersed hematite fine particles with calamitic liquid-crystalline organic phosphates enabled us to obtain a novel-type of organic-inorganic hybrid thermotropic liquid crystals (LCs). It is revealed that the key for the hybridization is the specific adsorption of the phosphate group to the surfaces parallel to the c-axis of the hematite particles. The hybrid LC shows thermotropic nematic or cubic liquid-crystallinity in wide ranges of temperatures. Variable-temperature small angle X-ray measurements reveal that the spontaneous formation of periodic structure by the hybridization induces the thermotropic liquid crystallinity.

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X-Ray single crystal structure analyses have been performed on three-ring diester and four-ring bis-anil compounds, both of which are of bent-core type and constitute mesomorphic derivatives showing B phases. The diester, 1,3-phenylene dibenzoate (1), crystallizes in P21/c space group, and the packing motif for molecules of the lowest symmetry (point group C₁) was characterized by polar carbonyl correlations unsymmetrical for the two arms. In contrast, the bis-anil, 4,4'-(disalicylideneamino)diphenylmethane (2), was found to be of C₂ symmetry and pile up orthogonally to form a block, which in turn pack into the P-1 space group. The distinctiveness has been interpreted based on the conformational flexibility in and between the arms. Implications to the mesophase structures will be discussed.

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A new non-symmetrical dimeric liquid crystal including two distinct mesogenic groups, 4-(4-fluorobenzoyloxy)phenyl cholesteryl decanedioate was synthesized and the mesomorphic properties were studied by a differential scanning calorimeter and a polarizing microscope. In addition, analogous compounds were synthesized with changing the position and/or the number of fluorine substituents, and the mesomorphic properties of these compounds were studied by the same methods in order to investigate the effects of fluorine substituents.

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We have designed a novel tetra-mesogenic liquid crystal, N, N'-di{3,5-bis[6-(4-(5-octylpyrimidin-2-yl)phenoxy)hexyloxy]benzoyl}-1,6-diaminohexane, and investigated the phase transition behaviour by means of polarized optical microscopy and differential scanning calorimetry. The transition behaviour of the tetramer was found to depend on the thermal history, i.e., the tetramer exhibited different phase transition behaviour by cooling from different temperatures above the melting point. We discuss aggregative effect of mesogens in the liquid-crystalline oligomer on the kinetically-driven phase transition.

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The rodlike molecules, 4-alkoxy-3,5-bis(hydroxymethyl)benzoic acids, possessing two hydrogen bonding sites in the direction of short axes were synthesized and their thermal transition behavior was investigated. These molecules showed smectic liquid crystal phases with alkylamines investigated with polarized optical microscopy, differential scanning calorimetry, and X-ray diffraction. The effect of hydrogen bondings in the direction of short axes was examined in comparison with the single crystal X-ray structure of an ester derivative.

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We designed a homologous series of novel dimeric liquid-crystalline compounds in which two mesogenic groups are connected via a cis-2-butene-1,4-diol and investigated the phase transition behavior. Phase sequence of the symmetric dimers was similar to that of corresponding monomoeric compounds. The non-symmetric dimer possessing phenylpyrimidine and cyanobiphenyl moieties exhibited a phase sequence of Iso-SmA-Cry. The SmA phase is thought to be induced by interaction between the mesogenic moieties. On the other hand, the non-symmetric dimer possessing methoxybiphenyl and cyanobiphenyl moieties was found to show a phase sequence of Iso-N-Cry. However, a one to one mixture of the corresponding monomeric compounds did not show a liquid crystalline phase.

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Mesomorphic Phase and its structure were studied in the two fuorine-containing conpounds, 2-(4-alkoxyphenyl)-5-trifluoromethylpyridine and a-(4-(4'-alkoxyphenyl)benzylchio)-w-(4-(4'-alkoxyphenyl)benzyl-chio)perfluoroalkane using DSC and X-ray scattering measurements and POM observations.In the former compound, the SmA layer spacing is larger than the molecular length just as CF3 gorup, suggesting the CF3 groups are separated in the SmA phase. In the latter compound, the spiral SmA phase was observed, which were shown in binary systems. Both results show that the fluroine atoms affect on the specificity of the mesomorphic structure.

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We are currently synthesizing the compounds with mesomorphic properties and gelling abilities to elucidate the molecular arrangement of gel states from the packing model of liquid crystalline states. In this paper, we select a triphenylamine structure as a central core of organogelators with mesomorphic properties because the triphenylamine structure has attracted much attention as a hole transport material of organic EL devices. The triphenylamine derivatives with three benzoylamino groups showed both mesomorphic properties and gelling abilities.

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Four kinds of esters combined 2-oxochromen-6-ol and 3H-2-oxopyran-5-ol with (S)-4-(2,6-dimethylheptyloxy)benzoate and (S)-4-(3,7-dimethyloctyloxy)benzoate exhibit smectic A phase and simultaneously can gelate several organic solvents. The gel fibers were characterized by XRD and SEM observations and circular dichroism. It is clarified that the Cotton effect and the sign are closely correlated with the helical structure and molecular properties such as the absolute configuration of the chiral atom and the carbon number between ether oxygen and chiral carbon. The correlation between the fine structure of gel fibers and the layer structure of the smectic A phase will be discussed.

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We have established the synthetic method for all-organic chiral liquid crystalline materials which contain a chiral five-membered cyclic nitroxide unit within the rigid core and can show various calamitic mesophases. Here I report the preparation of racemic and enantiomerically enriched liquid crystalline matereials, which can show a nematic, chiral nematic, smectic C, or chiral smectic C phase over a wide temperature range, and their optical and magnetic properties.

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We synthesized photoresponsive chiral dopant D1 and investigated its ability to alter the chirality of a liquid crystal. The chiral dopant was added to LC mixture of PCH302 and PCH304, followed by observation of polarizing optical microscopy. We found that isomerization of (R)-D1 between the open and closed form induced a change in the chirality of the chiral nematic LC from right handed to left handed screw direction.

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We have prepared T-shaped and bent-shaped chiral compounds possessing molecular biaxiality and investigated the physical properties. Both compounds were found to have a same magnitude of twisting power in the chiral nematic (N*) and chiral smectic C (SmC*) phases. However, only the T-shaped chiral compound exhibited a blue phase with a wide temperature range on cooling. Moreover, the compound induced a twist grain boundary phase in the binary mixture with its corresponding monomeric compound.

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We report results of small-angle X-ray scattering measurements of ANBC-22 undergoing phase transition from Smectic C (SmC) to cubic (Im3m) phase in 130 ~ 175 degC (heating process) at 35MPa. It was found that the phase transition follows a kinetic pathway with a transient structure which is an incomplete Im3m cubic phase. Furthermore, the transient structure exists within 7 degC during the heating process, and it gradually transforms into a perfect Im3m structure. It was also found that the spacing of SmC exhibits a discontinuous shrink upon the phase transition.

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Phase behavior and the structure of thermotropic cubic mesophase of hydrogen-bonded liquid crystalline compounds, 1,2-bis(4'-n-alkoxybenzoyl)hydrazines, denoted BABH-n, where n is the number of carbon atoms in the alkoxy group, were examined. The cubic phase was observed (at present) for n longer than or equal to 6, and as n increases, the temperature region became initially wider and then narrow up to 10, and further increase in n again widened the region. The X-ray diffraction results showed that the structure of the cubic phase for n=6-12 is all identified as being of Ia3d type, with the lattice constant well in proportion to n, but, surprisingly, for n=14, another type, Im3m type is formed. IR studies revealed that the transition from crystalline to cubic phases is mainly due to the change of alkoxy tail conformation, but dissociation of hydrogen bonding also proceeds with increasing temperature, especially for n=8-10, resulting in the formation of lamellar SmC phase at higher temperatures.

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Liquid crystals and other soft condensed systems, such as lyotropics, microemulsions, polymers, gels, colloids, etc. can be categorized in the "Soft matter". Soft matter system has intrinsic "softness" due to the huge hierarchical internal structure related to the biological structure. "Liquid" state cannot construct the complex structure due to its fluidity, and "Solid" state cannot support the living process due to its toughness. It is quite reasonable that liquid crystal state play important role on the mechanism of the biological system.

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The dissipative structures were irreversibly induced in the nematic composites through a procedure that an electric voltage was applied in the direction perpendicular to the substrate surface of the cell in which the molecules were uniaxially oriented in the plane by rubbing treatment. The striped pattern is possibly formed by electrically induced reorientation of directors. We discuss: 1) the transient behavior of structure formation for composites thorough the evaluation of optical texture and dielectric constant, 2) the structural model for memorized pattern. The periodicity of the pattern structure was determined in the early stage during application of an electric voltage. The resultant dielectric constant and texture indicate that the tilted director of the composites was pinned after removal of an electric voltage. The incident beam angle dependence of resultant periodicity evaluated from the diffracted light indicates that the pattern probably consists of positive and negative tilted director domains, of which the absolute angle was equal.

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We study a shape change of spherical microemulsion droplets when water-soluble polymers are confined inside of them. Upon confinement, spherical droplets deform to prolate ellipsoid droplets while keeping the total surface area and the total enclosed volume of all the droplets constant. We found that an increase of the degree of polymer confinement causes an increase in the uniaxial anisotropy of the prolate droplet, which leads to an isotropic - nematic transition in the concentrated droplet region.

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Chiral liquid crystal monolayers/films are known to exhibit two-dimensional liquid crystal order such as Smectic-C phase in which long axes of constituent molecules are uniformly tilted to the layer normal. It has been observed in experiment that orientations of liquid crystal molecules in Smectic-C phase collectively rotate when the transmembrane vapor flux exists. This collective rotation leads to formation of target patterns with propagating waves of orientation. In this paper we construct a phenomenological model of this phenomenon taking hydrodynamics and chirality into consideration. We carry out numerical simulations using this model and discuss effects of hydrodynamical flows on the pattern formation.

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Many lyotropic liquid crystal phases can be found in biological bodies, and there is no doubt that the liquid crystalline state plays an intrinsic role in the life of biological systems. On the other hand, chirality can produce huge hierarchical structures, such as tubules and ribbons etc., because the helix competes with the spatially uniform liquid crystalline order. Here, we have found a novel type of photonic liquid crystal, the SmBPIso, which for the first time, shows an optically isotropic but spontaneously iridescent color. The SmBPIso is characterized by the simultaneous presence of the finite local order parameter of an helix and of a smectic layer, while being spontaneously isotropic without any characteristic discontinuity on a mesoscopic length scale.

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We prepared a homologous series of bimesogenic liquid crystals in which cyanobiphenyl and phenylpyrimidine moieties are connected via a flexible spacer. The interdigitated SmCanti phase was found to be induced for some binary mixtures between the bimesogenic compounds with a different odd-numbered spacer. A striped pattern was observed for the SmCanti phase of a homeotoropically aligned sample. We investigated structure-property relationships in the binary system. Furthermore we designed a novel liquid crystal trimer and found an unusual texture of the SmC phase.

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To estimate chiral effect on optical properties of polymer network/chiral liquid crystals composites, chirality dependence of extinction ratio and electric-field induced birefringence were measured. All composites exhibited low extinction ratio at an temperature range above clearing point Tc and continuous increase of that below Tc. These datas indicated that optically isotropic polymer-network suppress the growth of macroscopic anisotropy of liquid crystals. Also the extinction ratio was chirality dependent. The lower concentration of chiral dopant in the composites, the higher extinction ratio was observed, which indicated the chirality had an important role for the macroscopic orientation of liquid crystals. Between the extinction ratio of the composites composed of blue phase liquid crystals and chiral nematic liquid crystals, a change of the chirality dependence was observed, indicating the change of molecular arrangement of liquid crystals. The electric field induced birefringence was also chilality dependent. The lower concentration of chiral dopant in the composites, the higher birefringence was observed, which could be accounted for the critical electric field necessary for unwinding the helix.

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We consider how the friction drag of a spherical particle in a liquid crystal just above the isotropic-nematic transitionis influenced by the nematic order induced at the particle surface.To this end, we solve the hydrodynamic equations for the second-rank tensor order parameter and the fluid velocity.We pay our main attention to the effect of the following four parameters on the friction drag:the strength of the surface order, the fluid velocity, the particle radius, and the temperature.

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We investigate with the aid of the Landau-de Gennescontinuum theory the interaction between two spherical particlesmediated by the elastic distortion of a nematic liquid crystal.We consider a case where the two particles are connected by a birefrigent string-like region that is called "a bubble-gum configuration." By numerical calculations we find that the interaction is attractive and its force is almost independent of the inter-particle distance,in strong contrast to any other elastic-distortion-mediated interaction in a nematic liquid crystal previously argued.These numerical observations are consistent with previous experiments.

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Relaxation of liquid crystalline order is calculated by applying a fluctuation dissipation theory in microscopic point of view. Decay rate is estimated form 2-time correlation function of nematic order parameter. Numerical calculations are carried by Monte-Carlo method using an approximate representation. The Monte-Carlo system is composed 1024 Gay-Berne molecules in a tetragonal cell with periodic boundary condition. Temperature dependence of the relaxation and molecular shape dependence are studied by changing molecular length.

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We discuss a nematic ordering of a system sandwiched by parallel boundary walls of biaxial anchoring in the framework of Maier-Saupe model basing on statistical mechanics theory. Biaxial character of molecular orientational distribution on the wall is shown to suppress the nematic ordering. The condition under which the crossover between homeotropic and homogeneous structures occurs is studied in detail.

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At a nematic system in the general condition exposed to two different kinds of external fields, e.g., electric and magnetic fields, a new order parameter called here an oblique axial order parameter is shown to be taken into account in addition to a uniaxial order parameter together with a biaxial one to describe transition phenomena correctly. Molecular formalism for the Maier-Saupe model is justified in an expansion form of order parameters. An effect of the oblique axial order parameter is demonstrated by studying a transition behaviour of the system in both of uniaxial and biaxial fields.

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