The spontaneous formation of bulk heterojunction active layer was studied for the blends of two types of liquid crystalline phthalocyanines as p-type semiconductor and PCBM as n-type one. The blends are the mixtures of the decyl homologue of non-peripheral (np)-phthalocyanine mesogen and the corresponding Zn complex, both of which show the comparable carrier mobility (〜10^<-1> cm^2 V^<-1> s^<-1>) in the Col h mesophase. The thermal phase transition property was clarified for the blends and the drift mobility of charged carriers were measured by TOF method. The correlation between the morphology of blends and carrier transport property was discussed.

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A mixtures of asymmetric and symmetric di(5'-octyl-2'-thienyl)naphthalene (8TNAT8) were studied on charge carrier mobility correlated to the mesomorphism. Mixtures of 2,7- and 2,6-8TNAT8 exhibit a highly ordered smectic mesophase. The introduction of asymmetric alkylthieno groups on naphthalene core part leads to the increase of dissolution into organic solvents during disappearance of mesophase in comparison to symmetric one. TOF measurements of carrier mobility were carried out. The observed mobility for positive carriers is 0.8〜1×10^-1cm² V^-1 s^-1 in the mesophase.

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The number of n-type liquid crystalline semiconductors has been limited. We have already reported that perylene tetracarboxylic bisimide derivatives bearing oligosiloxane chains exhibit columnar phases and efficient electron transport characteristics at room temperature. In this study, we synthesize PTCBI derivatives having various alkyl spacers and oligosiloxane chains and investigate the influence of the length of alkyl spacers and branching pattern of oligosiloxane chains on their mesomorphic properties and carrier transport characteristics.

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Liquid crystalline perylene tetracarboxylic bisimide derivative 1 bearing four disiloxane chains was synthesized. Compound 1 exhibits a hexagonal ordered columnar phase at room temperature. In the columnar phase, disiloxane chains interdigitate to stabilize the columnar structure. In the columns, molecules are closely stacked. The time-of-flight measurement reveals a high electron mobility exceeding 0.1 cm²/Vs in the columnar phase at room temperature. Compound 1 is soluble in various organic solvents and LC thin films can be produced by a spin-coating method. In particular, uniaxially aligned LC thin films can be formed on friction-transferred substrates.

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We synthesized oligothiophene derivatives bearing oligosiloxane chains at the ends of the alkyl chains. Diphenylterthiophene derivatives having disiloxane chains exhibits high solubility in organic solvents because of the thermal movement of the oligosiloxane chains. On cooling, fibrous structures were formed based on nanosegregation between rigid π-conjugated moieties and flexible oligosiloxane chains. We will also report carrier transport characteristics of the materials.

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We have investigated the molecular orientation and field-effect mobility of pentacene thin films formed on very thin photo-aligned polyimide films. The exposure of linearly polarized light in photo-alignment treatment was varied up to 300 J/cm². The molecular orientation, field-effect mobility, surface morphology, and crystallinity of the pentacene films were determined by polarized infrared absorption, current-voltage characteristics of pentacene-field effect transistors, atomic force microscopy, and X-ray diffraction, respectively. Their light exposure dependence will be discussed.

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Charge carriers in randomly aligned and randomly oriented molecules are affected on their random hopping transport by locally different carrier-dipole interaction (Gaussian disorder model proposed by Bassler). In liquid crystalline semiconductors, however, the disorder mechanism depends on their structural order of liquid crystals. High performance of carrier transport is achieved in these ordered materials. In this research, we demonstrate how the mechanism affects the performance of the device materials exhibiting liquid crystalline phase. In OFETs, for example, we showed that the order of liquid crystalline alignments not only provide high mobility but also decrease the effect of energetic disorder from the interface of gate insulator on OFETs performance.

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We have developed a new soluble liquid crystalline FET material of beozothienobenzothiophene derivative having highly ordered liquid crystal phase and investigated the polycrystalline thin films fabricated at various temperatures. It was found that uniform thin films were fabricated not only at high temperature over 100℃ but also at a low temperature of 65℃. And the FET fabricated with the polycrystalline thin films exhibited a high mobility over 5 cm^2/Vs, which was hardly changed even after the thermal stress up to 140℃ for 5 min. This new material is very promising for practical applications of FET.

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Easy axes of a rubbed Polyvinyimidazol (PVI) film have been investigated in different liquid crystals. MBBA aligned parallel to the rubbing direction and 5CB aligned perpendicular. The PVI film surface was also rubbed by silicone rubber sheet and the rubbed surface had no micro-grooves. The same LC dependence of easy axis can be obtain as the rubbed surface by using clothes of polyester, rayon and cotton. Microgrooves, therefore, does not contribute to the parallel alignment to the rubbing direction, in the case of MBBA.

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It’s well known that surface relief (SR) structures in azobenzene polymer films are fabricated due to molecular migration by holography with intensity and polarization patterns of two beams interference. Blazed SR gratings, which exhibit asymmetric SR structures, exhibit asymmetrical diffraction properties, so those are useful as diffraction optical devices. Because molecular migration occurs symmetrically according to the symmetrical interference pattern, the blazed SR formation using conventional holographic techniques have not been reported. In this work, we demonstrated control of SR structure in azobenzene polymer films using controlled polarized two-beam interference.

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Previously, we prepared donor-acceptor dyad (1) linking a discotic liquid-crystalline phthalocyanine (Pc) and fullerene (C_<60>), and established the perfect homeotropic alignment from room temperature. However, the synthetic route was so long that the total yield was low. This is a big problem for their pratical applications. In this work, we have successfully prepared a novel type of dyads (2a and 2b) consisting C_<60> and a Pc directly substituted by alkylthio groups, by using an easy synthetic method. Furthermore, we found that the dyads also show homeotropic alignment and helical structure of C_<60>.

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Previously, we prepared the phthalocyaninato copper(II) complexes substituted by eight p, m, m'-trialkoxyphenoxy groups, abbreviated as [(C_nO)_3PhO]_8PcCu, which show a wide temperature range of Cubic mesophase irrespective of a disk-like molecule. Cubic phases are still unclear and fascinating mesophases. There have been only four examples showing Cubic phases in discotic liquid crystals including this [(C_<14>O)_3PhO]_8PcCu complexes. In this work, we have successfully synthesized a novel phthalocyanine-fullerene dyad, [(C_<14>O)_3PhO]_6PcCu-C_<60>(1), and investigated the mesomorphism.

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We have synthesized thirty-four novel homologous discotic liquid crystals, octakis(m-alkoxyphenoxy)phthalocyaninato metal(II) {abbreviated as (m-C_nOPhO)_8PcM (M=Co, Ni, Cu, Zn and H_2; n=8, 10, 12, 14, 16, 18 and 20)}, and investigated parity effect of the number of d-electrons on the stacking distances in their columnar mesophases. It was revealed from temperature-dependent wide angle X-ray diffraction studies that each of the cobalt(II) (d^7) complexes and the copper(II) (d^9) complexes showed a single hexagonal ordered columnar (Col_<ho>) mesophase with a very short stacking distance at 3.3Å, and that the nickel(II) (d^8) complexes and the metal-free (d^0) derivatives showed a single pseudo-hexagonal ordered columnar (Col_<rho>) mesophase with a little bit longer stacking distances at 3.4Å. Furthermore, the zinc(II) (d^<10>) complexes showed two different rectangular ordered columnar mesophases, Col_<ro>(P2/m) and Col_<ro>(P2_1/a), with a little bit longer stacking distance at 3.4Å.

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Previously, we reported that a series of phthalocyanine (Pc) derivatives substituted by bulky aryl groups without long alkyl chains show columnar mesomorphism, and that they are novel flying-seed-like liquid crystals. These flying-seed-like liquid crystals may be applicable to solar cell, and they can be expected to show high conversion efficiency. In this work, we have, hence, synthesized novel dyads consisting of this flying-seed-like Pc and a fullerene to investigate their mesomorphism by using a polarizing microscope, a differential scanning calorimeter and a temperature-dependent X-ray diffractometer.

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Electro-rheological (ER) fluids whose viscosity is controlled by applied electric field strength have been widely studied as smart materials for industrial utilities. We have studied ER effect of the liquid crystalline (LC) materials which have various siloxane cores. It has been found that the response time of the viscosity to the applied electric fields and the increase of the viscosity depended greatly on their molecular structure. We demonstrate the characteristic phenomena on ER effect of the siloxane LC materials.

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Two types of photofunctional materials based on well-defined azobenzene LC polymers were developed. Diblock copolymers consisting of an LC unit and an amorphous unit were prepared by ATRP as holographic materials. Effect of microphase separation on photoisomerization and photoinduced alignment behavior as well as on holographic properties was explored in details. Furthermore, bilayer films composed with a crosslinked azobenzene LC polymer layer and a flexible polymer layer were fabricated by surface-initiated ATRP as photomobile materials. The bending direction of the films could be selected by a change in polarization direction of incident UV light due to in-plane aligned mesogens with a polydomain structure. This is the first example of fabrication of photomobile polymers based on azobenzene LC polymer brushes tethered on polymer substrates.

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The properties and structure of the liquid crystalline (LC) colloid of the clay mineral nanosheet, fluorohectorite (FHT), dispersed in dimethylformamide (DMF) was investigated as the functions of the concentrations of a salt, water, and the nanosheets. The FHT/DMF system showed birefringence due to the LC phase above 0.5 wt. %. Small angle X-ray scattering revealed the presence of the lamellar structure in the LC phases, whose basal spacing decreased as the nanosheet concentration increses or a salt is added. Addition of water to FHT/DMF system resulted in the decrease in basal spacing and increase in structural regularity. The viscosity of the system significantly increased as the salt was added.

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Colloidal dispersion of the inorganic nanosheet derived from a layered clay mineral montmorillonite was found to show liquid crystal phase. The structural regularity of this liquid crystal increased drastically by the addition of a small amount of anionic polymers such as polyacrylic acid and DNA as revealed by small-angle X-ray scattering measurements.

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We propose the novel alignment methods for the nematic liquid crystal cells coated by low glass transition polymers without the rubbing. We aligned liquid crystals by applying a magnetic field parallel to the substrates in the higher temperature, where the polymers are melted into the liquid state, but liquid crystals still keep the nematic state. Then, after cooling the cell below the glass transition temperature of the polymers, we found that the alignment direction was fixed and homogeneously aligned nematic liquid crystal was obtained automatically. Comparing self-alignment nematic liquid crystals with the conventional rubbing method, we found that the anchoring strength of PMMA thin films was completely independent of aligning process. This result evidently concludes that physical mechanisms of "alignment" and "anchoring" of liquid crystals on the polymer surface are intrinsically distinguished from each other.

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In amphiphilic liquid crystal molecules with hydroxyl end group, it has been reported that the molecules exhibit three types of the Smectic C phases. In these phases, monolayer (SmC) and bilayer (SmC', SmC") orderings were observed using the conventional X-ray diffraction (XRD). In this study, we investigated more detailed structures in the SmC' and SmC" phases using the high resolution small angle XRD. In summary, we found that the SmC" phase has a conventional bilayer structure and the SmC' phase has a frustrated bilayer structure.

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The resonant X-ray scattering measurement is a powerful tool for obtaining direct information on the super-structure of the chiral smectic liquid crystals. Recently we have successfully applied the microbeam resonant X-ray scattering (XRS) to the characterization of the novel Br-substituted bent-core liquid crystal B2 phase in the cell structure. Furthermore, we studied the super-structure of mixtures composed of this bent-core molecule and MHPOBC by micro-beam XRS, the different resonant peaks were observed from those in the pure compound. Based on the results, we discuss the effect of chiral doping on the super-structure of the mixtures.

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We have found the new principle. i.e., helix untangled C-director anchoring in the homeotropically oriented chiral smecitc C (SC^*) phase. When homeotropically oriented SC^* phase, which is swollen by the photo curable acrylate monomers, is illuminated by UV light under appropriate in-plane DC electric field to unwind the helix, polymer nano-sheets are heterogeneously polymerized between the neighboring smectic layers, and anchor the C-director uniformly under the helix untangled state. In order to check the switching dynamics of the helix untangled C-director anchored state, we applied a rectangle pulsed electric filed E horizontally along the parallel to the layers. Transmitted light intensity between crossed Nichol polarizers, is quickly changed responded to E due to the interaction between the spontaneous polarization and the external electric filed. The response time of the C-director anchored sample is almost equivalent to the original SC^* phase (<1msec at 30℃). The response time is strongly dependent on the concentration of intercalated acrylate monomer and temperature.

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Triphenylene has been widely used for a mesogenic core for discotic liquid crystalline (LC) materials. However, its LC derivatives, possessing side chain (R) via a -C(O)OR- type ester linkage, have not been studied so far. Recently, we investigated on the assembling behaviors of a series of LC TP(CO_2C_nH_<2n+1>)_6 and demonstrated that a dipole-dipole interaction among their ester carbonyl groups enables an exceptionally wide-range 2D lattice correlation in hexagonal columnar LCs. Being encouraged by this finding, we newly designed TP(CO_2R)_6 with semifluoroalkyl terminal chains. Since fluoroalkyl chains are known to aggregate strongly, we expected that such an interaction among fluoroalkyl side chains, in addition to the dipole-dipole interaction, could lead to further enhancement of 2D lattice correlation. Here, as an extension of our previous work, we also investigated the phase behavior of a TP(CO_2R)_6 derivative carrying imidazolium ion-appended paraffinic side chains.

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The alkyl homologues of azobenzene-triphenylene mesogen(C11-C16) were studied on both thermal and photo-induced phase transitions by DSC, POM and XRD measurements. All homologues exhibit SmA and Colr mesophases and only C12 and C11 possesses SmC phase as the additional mesophase. The clearing points show an odd-even effect. Interestingly, photo intensity dependence on isothermal phase transitions is dependent on the chain length.

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Multi-bilayered films having optical periodicity with different refractive indices have been studied for one dimensional photonic crystal (1DPC) showing photonic band gap (PBG) in which the existence of a certain energy range of photons is forbidden. In this study, photo-responsive multi-bilayered film consisting of azobenzene polymer liquid crystals and polyvinyl alcohol were prepared on a glass substrate by spin coating, and we investigated effects of azobenzene structures on their optical and photoresponsive properties.

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In this study, the photo-responsive liquid crystalline films which contained an azobenzene compound in a nematic liquid crystal as a host material was prepared. We estimated the manipulation of micro-meter-sized particulates on the film. Investigated with UV or Visible light irradiation, the motion of the micro particles was caused. The mechanism of the photo-responsive motion was discussed.

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Liquid-crystalline azobenzene block copolymers with poly(butylmethacrylate) block were synthesized by atom transfer radical polymerization. Thin films of the polymers were prepared by spincast method. The films were irradiated with linear polarized visible light (LPL) under liquid crystal phase under LC temperature. The resulting film exhibited the in-plane anisotropy in smectic phase and the microphase separation structure aligned perpendicular to the polarization plane of the LPL. We evaluated orientations of LC phase and microphase separation structure by the polarized absorption spectroscopy and grazing incidence small angle X-ray scattering (GI-SAXS) measurement. Moreover in order to reveal the photoreorientation behavior, we estimate the reorientation domain size from the half-band width of the GI-SAXS data and the polarized microscope measurement at the intermediate state of the photoreorientation process.

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We prepared some crown ether derivatives possessing phenylpyrimidine or cyanobiphenyl as a mesogenic unit. Those compounds were tested against A549 human lung cancer cell line. They were found to show marked suppression of cell proliferation. The cell cycle analysis indicates that the crown ether derivatives induce cell death in the tumor cell. Furthermore, we investigated effects of mesogenic structure on the anticancer activity. The phenylpyrimidine derivatives induced necroptosis, while the cyanobiphenyl derivatives induced necrosis.

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We investigated anti-cancer activity of mesogenic compounds possessing a hydroxyl group. The compounds were tested against A549 human lung adenocarcinoma cell line. Three ring heterocyclic derivatives containing a phenol unit showed significant suppression of the cell growth. The cell cycle analysis indicates that these compounds induce apoptosis. To determine the influence of these derivatives on normal cells, they were tested against WI-38 human lung fibroblast cell line under the same condition. Very interestingly, suppression of the normal cells was found to be dependent on the core structure of the mesogenic moiety. Some compounds induces apoptosis selectively against the tumor cell without suppressing the normal cell.

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Liquid crystal (LC) microwave phase shifter based on microstrip line has been investigated by introducing novel conversion circuit structure. The new circuit enables us to integrate LC materials easily with the high frequency electronic circuits. However, the operational frequency has been limited by about 10GHz so far. In this work, device structure is optimized by FDTD simulation to improve the performance and excellent phase shifting properties in MMW region can be attained.

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We propose a liquid crystal (LC) composite device with two pairs of a twisted nematic (TN) LC cell sandwiched between two cholesteric (Ch) LC filters at same wavelength of the selective reflection. The transmission and reflected light intensities at two different near infrared wavelengths of 850 nm and 1300 nm can be changed selectively by applying the voltages to each nematic LC cell. The reflected signal level and the position of the plural LC composite devices attached at the end of optical fibers can be determined by using an optical time domain reflectometery (OTDR) system.

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We report a high-speed electro-optic response in cholesteric liquid crystals(ChLCs). The ChLC device consisted of an anisotropic polymer matrix possessing helical order embedded with nanosized pores filled with a ChLC. LC molecules confined in the nanopores showed the high-speed electro-optic response, reaching a decay time of 6μs.

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Nonlinear light propagation in a dye-doped nematic liquid crystal (LC) was investigated experimentally. A laser beam with wavelength far from the absorption peak of the material was coupled into an LC cell with homogeneous alignment, and the propagation in the cell was observed. When the polarization azimuth of the incident light was orthogonal to the orientation direction of the LC, soliton-like propagation was obtained for milliwatts of light power in spite of the low absorption. We clarified that the observed nonlinearity is due principally to the photothermal effect enhanced by the dye.

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Photorefractive effect of Ferroelectric liquid crystals (FLCs) under application of alternating electric field was investigated. The consecutive rotational switching motion of FLC molecules with an applied alternating electric field was modulated by the photoinduced internal electric field at the interference fringe. The effect of the mechanism of the photoconductivity on the photorefractive effect was investigated.

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Dye-doped liquid crystalls (LCs) exhibit significantly enhanced photoinduced reorientation compared to undoped LCs. In this study, photoresponsive behavior of LC systems doped with photostable fluorescent dyes were investigated. Photoresponsive behavior of the LC system was evaluated by the self-diffraction pattern formed upon irradiation of a linearly polarized Ar^+ laser beam. When the laser beam was incident on the sample cells, clear diffraction pattern was observed for the sample cells doped with Coumarin 6 and Coumarin 7. Thus, they were found to act as a trigger for the photoinduced reorientation.

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Microstrip line structure has been mainly used in microwave phase shifter using liquid crystal, but there is a serious problem about the response time upon voltage removal. Polymer stabilized nematic liquid crystal, in which a mesogenic monomer is doped into a nematic liquid crystal and is polymerized in the nematic phase, shows short response time upon voltage removal even in the thick cell. In this study, we discuss the response time of microstrip-line-type microwave variable phase shifter using polymer stabilized nematic liquid crystal with thermal polymerization.

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A broadband liquid crystal loaded microstrip-line (MSL) to coplanar waveguide (CPW) transition with easy-to-make structure and highly efficient transmission for various applications in microwave bands devices of liquid crystal is proposed in this study. The fabricated transitions provide insertion loss less than 2dB and return loss of about 10dB for frequencies from 10GHz to over 30GHz. In addition, to downsize liquid crystal loaded microwave device, a liquid crystal molecular orientation control circuit, composed of bias T and low frequency reject filters, is integrated into the transition substrate.

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The chiral smectic C phase of ferroelectric liquid crystals (FLCs) has a self-assembling helical structure which is regarded as a one-dimensional pseudo-photonic crystal. It is well known that a stopband of a FLC can be tuned in wavelength domain by changing temperature or electric field. We here have demonstrated an FLC stopband with independently tunable wavelength and bandwidth by controlling temperature and incident angle. At highly oblique incidence, the stopband does not have polarization dependence. Furthermore, the bandwidth at highly oblique incidence is much wider than that at normal incidence. The mechanism of the tunable stopband is clarified by considering the reflection at oblique incidence.

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Liquid-crystalline epoxy resins have high thermal conductivities. Its high thermal conductivity results from highly ordered molecules in the smectic structure. Alignment order of molecules are significant factor for the thermal conductivity. In the present study, we examine molecular dynamics simulation to estimate alignment order of molecules of epoxy resin. Relation between the obtained alignment order and thermal conductivity is discussed and recipe to develop epoxy resin of higher thermal conductivity is also presented.

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The orientation of liquid crystaland defects included in it can be evaluated by the observation of the reorientation process after the orientation is distorted by a pulse light. In this study, we utilized transient grating method, by which photochemical change can be observed by way of the refractive-index variation. The used sample is (N-(4-methoxybenzylidene)-4-butylanil-ine: MBBA), which is a typical nematic liquid crystal. The reorientation dynamics was observed and we found the orientation change depending on the light intensity, and we proposed a domain of the liquid crystal was reoriented for the higher pump intensity.

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Using a coaxial double cylinder type viscometer, dielectric properties of ferroelectric liquid crystal 2M45OBC(2-methylbutyl-4'-n-pentyloxy-biphenyl-4-carboxylate), which has a phase sequence of be K-S_C^*-S_A-I, have been measured focusing on the ferroelectric S C^* to S_A transition. The temperature and frequency dependence of dielectric constants show that in spite of no orientational treatment, characteristic ferroelectric behaviors were observed, showing that in the viscometer polarization is spontaneously alignment along the electrodes. On the basis of these results, the spontaneous orientation of ferroelectric liquid crystal and the appearance of ferroelectricity in the viscometer will be discussed.

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Liquid crystal states can produce various high-order structures such as the blue phase. High performance materials having the nano structure are expected to be achieved by low energy consumption in the utilization of the liquid crystal state. In the present study, we focus on the photochemically polymerizable mesogenic monomers, and then, try to produce the blue phase with the monomers, solidificate the blue phase structure by the photocure, and investigate the physical properties of the soliditicated matter for the application to the nano-structured materials.

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It has been reported that a solid-like interfacial layer can be formed between polymer sublayers and liquid crystals. In the present study, the thickness dependence of viscoelasticity of liquid crystal thin film was investigated using a quartz crystal microbalance (QCM). The results indicate that thin liquid crystal film of 23 nm thick or thinner exhibited solid-like characteristics without liquid crystalline properties.

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It is known that B_4-B_x transition appears in the mixture of the rod-like liquid crystal (5CB) and the bent-core liquid crystal (P8OPIMB), which is understood to correspond to the I-N transition of 5CB. In this study, heat capacity measurements have been made on mixtures of bent-core azo compound 12OAz5AzO12 and 5CB. We report the effect of addition of 12OAz5AzO12 molecules to the 5CB system.

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We had performed the AC calorimetric measurements on aerosil-dispersed liquid crystal systems and observed the frequency dependence of the phase response in N-SmA phase transition. It could be thought that this was the influence on the internal relaxation time by aerosil mixture. However, reliable analyses were difficult because the form of the present sample cell is a different form from the standard theoretical models. In this study, we have used the sample cells with a new design that is nearer to the standard theoretical model, and investigated the influence on the N-SmA phase transition by aerosil mixture.

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Because the rotation around the molecular long axis plays an important role for the emergence of ferroelectricity in chiral smectic liquid crystalline materials, many investigations have been performed to clarify it. As for the dynamical aspect, however, the detail of the hindered molecular rotation is still open for the question, though several experimental approaches have carried out so far. In this report, we study molecular dynamics of chiral and achiral smectic liquid crystals, analyzing the ^<13>C spin-lattice relaxation time (T_1) and the half-width (H-W) of ^<13>C-NMR resonance peaks, which are estimated by means of solid-state ^<13>C-NMR spectroscopy with Larmor frequency ω_0 of 100MHz. The chiral and achiral smectic samples used are S-4-(1-methylhexyloxycarbonyl)phenyl 4'-octyloxy-biphenyl-4-carboxylate (S-MH(6)POBC) and 4-(hexyloxycarbonyl)phenyl-4'-octyloxybiphenyl-4-carboxylate (H(6)POBC), respectively. Temperature dependence of T_1 and H-W is measured in order to detect changes of their molecular rotation during the successive phase transformations.

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Porous silica microcapsules have been studied on a variety of functionalization such as DDS. Confined nematic liquid crystal has been intensively studied to reveal that much modification of phase transitions is caused due to the enhancement of interaction with surfaces of pores. In this work, the injection of nematic liquid crystal under reduced pressure was studied to clarify the condition in which the pore and inner space of the capsules are filled with the liquid crystalline molecules. In this work, some techniques were examined to inject a room-temperature nematic liquid crystal, 5CB, into the inner space of microcapsule under reduced pressure. Under 10^<-1> mmHg of the pressure, the injection was attained up to about 50% of the inner space of microcapsules of which averaged diameter is 10μm with the averaged pore size of 10 nm. The phase transitions were studied by DSC to reveal the two crystalline states are formed while the clearing point is not affected. This indicates that a macroscopic bulk nature of 5CB still exists and some portions of 5CB which are probably contacting the surface of silica is affected on its morphology probably due to the surface energy which will make change of nucleation of crystal.

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Side-chain liquid-crystalline polymers were synthesized by atom transfer radical polymerization (ATRP) method and conventional radical polymerization method. Effect of polymer main-chain on the liquid-crystalline phase structures was investigated by differential scanning calorimetry and polarized optical microscopy. Polymers synthesized by ATRP method showed larger ΔH_<S-N> values than those of polymers synthesized by conventional radical polymerization method.

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Liquid crystal compound (8BP(Cl)MB) which exhibits electric field induced phase transition in the cholesteric phase was synthesized. In this study, novel compounds (8BP(Cl)MB', 8BP(Cl_2)MB, 8FBPMB, 8FBP(Cl)MB) have been synthesized. Those componds possess substituents in different position on the mesogenic unit or the biphenyl unit. Phase transition temperatures and the textures under polarization microscope were measured. The relationship between the moleculer structure and the electric field induced phase transitions are discussed.

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We investigate the mesomorphic properties of main-chain chiral-smectic elastomers cross-linked in different phases, analyzing three samples prepared by photo-cross-linking a chiral smectic C (SmC^*) polymer in the SmC^*, SmA, and isotropic (Iso) phases. The SmC^*-cross-linked elastomer exhibits successive SmC^*-SmA-Iso transformations similarly to the precursor polymer. However, only the orthogonal molecular alignment due to the SmA structure appears in the SmA-cross-linked elastomer. Moreover, isotropic alignment remains in most of the Iso-cross-linked elastomer even at room temperature. Since the effect of the fixed orientation is not localized in the vicinity of cross-links because of the direct coupling between the mesogenic orientation and the polymeric conformation in main-chain smectic elastomers, the transformation from the cross-linked phase to a higher-order phase might be forbidden.

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