Recently, we have found that the upper plate of a rheometer spontaneously rotates when a nematic liquid crystal MBBA is sandwiched between the two parallel plates and an ac electric field is applied to the sample to generate electroconvection. The spontaneous rotation indicates the existence of negative shear stress and furthermore hysteresis loop of the shear stress vs. the shear rate. We have successfully observed hysteresis loops similar to those observed in ferroelectric and ferromagnetic materials. We also found that all the hysteresis loops with different electric fields fall on a universal loop when both the shear stress and the shear rate are scaled by squared electric field.

It has been reported that an “interfacial elastic layer” of liquid crystalline (LC) molecules was formed on a polymer sublayer. Within this layer a thin “restricted layer” was found to remain the polymer sublayer after evaporation of the LC in vacuum. In this study, we investigate the effects of substrate temperature on the thickness of the “restricted layer” on polymer sublayers for homogeneous orientation by using a quartz crystal microbalance (QCM). The results show that a diffusion of LC into polymer sublayer plays an essential role in the orientation of LCs. Moreover the diffusion can be suppressed by the rubbing of the polymer surface.

In the binary phase diagram of chiral molecules, MC881 and MC452, the transition line between anticlinic SmCA* and synclinic SmC* phases becomes apparently parallel to the temperature axis at the critical concentration, φc. The fact that subtle concentration difference changes clinicity in adjacent layers suggests that tilting correlation in adjacent layers will be weaken by the competition between synclinic and anticlinic structures. Nearφc, we confirmed that a driving voltage becomes low at the higher temperature region of SmCA*, while it is not low far from φc. In this paper, we measured the electrooptic properties depending on the concentration, and discuss the relation of tilting correlation and driving voltage or response time.

We observed the spontaneous shape change of a uniaxially oriented liquid-crystalline elastomer composed of smectic main-chain liquid-crystalline polyesters in a cyclic heating-cooling process. Although the elastomer contracted by about 650% on heating up to the isotropic phase, the sample length recovered by about 450% on cooling to room temperature in the first heating-cooling process. In contrast, the elastomer exhibited completely reversible deformation in the second heating-cooling process. The shape change occurred with almost no change in the orientational order of mesogens in the temperature region of the liquid-crystalline phase. The mechanism of the spontaneous thermotropic shape change is discussed.

In this report, 3 types of compounds, e.g., b-diketones, pyrazoles and isoxazoles were synthesized, three of each, and their properties investigated, for the total of 9 compounds. Generally, most of the b-diketone derivatives exhibited simple melting behavior, with some exceptions of a single short range smectic A phase. The long and flexible alkyl chain might result in this observation that it expelled the neighbor molecule away thus a smectic A was formed. In contrary, an oxygen atom in some types of compounds might raise intermolecular interaction and the molecules are too close together to form any mesophases. When pyrazoles were formed, four compounds exhibited mesophases while two were non-mesogenic. In starting materials, the b-diketone moieties are rather flexible even with an intramolecular hydrogen bond, however, the pyrazole moieties are more rigid and various mesophases were observed. As of isoxazoles, the moesophase trends were similar to those of the pyrazoles, except with higher transition temperatures of the formers. Nevertheless, the isoxazoles were non-mesogenic.

Analogous mesogens of non-peripheral type of hexahexylphthalocyanine (C6PcH2) were synthesized and studied on their mesomorphism and charge transport properties. All compounds exhibit columnar mesophases with slight difference in phase transition parameters. The number of N atoms at the meso positions in the macrocycle surely affects the mesophase variation as well as the thermal stability. On the other hand, carrier (drift) mobility was revealed to be in the order of 10-1 cm2 /Vs in an ambipolar manner which is comparable to those of C6PcH2.

A novel mesogen, a triphenylene derivative possessing six alkoxyazobenzenes at the periphery linked by ester groups exhibits bimesomorphism of calamitic and discotic mesophism with its shape change in anisotropy. The linkage group between triphenylene and azobenzene would take an important role in the occurrence of such a bimesomorphism. In this communication, a few derivatives of which linkage group is ether one instead of ester were studied on their mesomorphis to reveal the linkage groups take an critical role for such a bimesomorphism. Also the ether linkage leads to a drastic decrease of clearing point.

Three oxovanadium(IV) complexes of derivatives of chiral Schiff's bases have been synthesized and their properties investigated, Structure 1. They were similarly found to show only chiral nematic phases, while the intermediates exhibited some other phases, i.e., chiral smectic C and blue phases. Surprisingly, as the structures are in accordance to an ideal mesogenic moiety, the ester starting materials were non-mesogenic. This may be due to a rather weak intermolecular interaction of the ester groups in the adjacent molecules. Until after the hydrolyses of the esters that two from three of the resulting acid could form liquid crystal phases, two chiral smectic C and a chiral nematic phases. Then, condensing with 4-hydroxybenzaldehyde, again, gave another non-mesogenic intermediates. In contrast with the starting materials, these compounds might possess much higher intermolecular interaction for the molecules to form mesophases. On the formation of the imine derivatives, the Schiff's base ligand without oxygen showed a distinct Blue Phase II (BPII) texture. Finally, the oxovanadium(IV) complexes all showed only chiral nematic phases.

Polyurethane (PU) as an industrial material has been used in paints and adhesives, it is important materials in the modern. In the last few years, the study of the liquid crystal PU having a good liquid crystal groups of orientation for the modification of the PU has been actively conducted. In this study, we were synthesized the polyurethane with an azine unit which exhibit high thermal stability and light stability to the mesogenic groups. The obtained polyurethane was yellow powder of 67.2% yield.

We synthesized and evaluated liquid crystalline (LC) phases of novel benzoic acids with different alkylthio groups at each para-position. Their LC phases were characterized with polarizing optical microscopy (POM), differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD). The present molecules solely form a nematic (N) regime, owing to spontaneous carboxylic dimerization. It was found that the number of carbons in the alkylthio groups strongly correlated with transition temperatures as well as nematogenic stability; odd-even effects. Based-on WAXD measurements with aligned specimens, an alkylthio analogue exhibited the enhanced cybotactic clusters compared to an alkoxy analogue.

Previously, columnar liquid crystalline compound urea C10-H was synthesized in our laboratory [1]. Though urea C10-H showed a ferroelectric switching behavior, its polarity did not maintain because of the electrostatic repulsion between the columns. Here, compounds 1 and 2 introducing chirality were synthesized to stabilize their polarities. Their phase transition behaviors and liquid crystal structures were investigated by polarized light optical microscopy and X-ray diffraction. 1 and 2 exhibited columnar phases, and showed polarity switching in response to an applied electric field. The polarity of 1 maintained partially after removal of the electric field. Hence, 1 showed ferroelectric behavior at its columnar liquid crystal.

Using liquid crystals as media of chemical reactions is expected to enable highly-enantioselective-reaction.We focused on a chiral dopant 1 (Scheme1) . It is predicted that 1 thermally decomposes and recombines through retro-Diels-Alder and Diels-Alder reactions of anthracene and rod-like fumaryl ester. In a chiral nematic phase, it is expected that these reactions proceed with a favorable enantioselectivity due to the helical molecular alignment generated by 1. The purposes of this study are to pursue the behavior of 1 in liquid crystal phase and to realize spontenious chiral-induction. The mixture of 1 and host-LC was heated and the enantiomeric excess of 1 was monitered by HPLC.

In this presentation, we report on synthesis and cholesteric liquid crystal (CLC) features of alkane diol derivatives tethering two cholesteryl units at their terminal positions (Cn-DiCh). An ethylene glycol derivative (C2-DiCh) cell showed a Bragg reflection band in a wavelength range from 620 nm to 780 nm by stepwise cooling from 142 °C to 125 °C. We serendipitously found that some of Cn-DiCh cells annealed at CLC temperatures are supercooled to 0 °C, whereupon the reflection wavelength can be preserved even at room temperature. Such supercooling treatment resulted in durable formation of a glassy CLC solid-state without the aid of any covalent bonding.

Gold complexes are known to show strong luminescence in condensed phases caused by aurophilic interaction, and their luminescent properties can be controlled by changing the aggregated structures. We have developed luminescent gold complexes showing liquid-crystalline (LC) phase. These complexes can modulate their aggregated structure by phase transition, and showed multi-color luminescence behavior depends on their aggregated structure. To develop such gold complexes as functional materials, in this study, we synthesized novel gold complexes with a siloxane moiety at the terminal of flexible chain to lower melting point and expand LC phase temperature. In this study, we evaluated their phase transition behavior and photophysical properties in condensed phases, anddiscussed a relationship between their properties and aggregated structure.

We have investigated optical properties of retardation films with negative wavelength dispersion-birefringence (NWD) prepared by polymerizable liquid crystal materials. New liquid crystalline monomers suitable to a coating have been developed, and have also been optimized to improve optical properties and durability of the retardation film. Solubilities of new monomers were more than 20%wt in MIBK. We succeeded in fabricating retardation films having a homogenous alignment (+A plate) of which retardation ratio was 0.867 (450nm/550nm), and 1.017 (650nm/550nm). Furthermore, we also succeeded in fabricating retardation films having a homeotropic alignment (+C plate) or a hybrid alignment (O plate) with NWD.

A novel polar nematic liquid-crystalline (LC) molecule having a pyridyl moiety has been designed and synthesized. Complexation of the pyridine derivative and solvate ionic liquids (lithium salt coordinated by oligoether) resulted in the induction of smectic LC phases in wide temperature ranges. Raman spectroscopic study of the complexes revealed that the coordination structure of the solvate ionic liquid was preserved in the complexes. High lithium ion conductivities on the order of 10-4 S cm-1 have been achieved for the complexes in the oriented smectic LC phases.

A zwitterionic liquid crystal containing polymerizable moieties was designed and synthesized to develop nanostructured proton-conductive polymeric matrices. The equimolar mixture of the monomer and benzenesulfonic acid was prepared. Both of the monomer and the mixture exhibited hexagonal columnar liquid-crystalline (LC) phases. Photopolymerization of the monomer and the mixture in the LC states resulted in the formation of free-standing polymer films preserving the LC nanostructures. The photopolymerized mixture showed proton conductivities on the order of 10-7~10-5 S cm-1 between 30~150 °C, while for the polymerized zwitterionic molecule, lower proton conductivities on the order of 10-9~10-8 S cm-1 between 30~150 °C was observed.

Novel liquid crystalline polyaminourethanes and their ionic families were synthesized by polyaddition of mesogenic diols and diisocyanates. In the case of the liquid crystalline homopolyurethanes, which were synthesized from mesogenic diols with a tertiary amino group and diisocyanates, the repeating unit consists of a mesogenic group, tertiary amino group and diurethane core. On the other hand, the liquid crystalline copolyurethanes were synthesized by the reaction of mesogenic diol and diethanol amine with diisocyanate. The liquid crystalline polyurethanes exhibited a nematic phase on heating and cooling. The ionic family of the liquid crystalline homopolyurethanes formed a smectic A phase. However, the ionic family of the liquid crystalline copolyurethanes showed a nematic phase and did not form a smectic A phase. The ionic families revealed higher phase transition temperatures when compared to the liquid crystalline polyurethanes. Mechanical properties were examined for the liquid crystalline polyurethanes and their ionic families.

N,N'-dialkyl-4,4'-bipyridinium salts (viologen) are generally reduced by the action of an electric field or photo-irradiation. It is expected that viologens with two long alkyl chains show liquid crystal (LC). In thisstudy, extended viologens that an aromatic ring was inserted between two pyridine rings were synthesized. It was found that the viscosity of the extended viologens was lower as compared with that of general viologens, and the extended viologens exhibited mesophases. In result, the photochromism was notobserved in the extended viologen films, however the LC-Isotropic transition temperature was lowered after irradiation with UV light.

Asymmetric alkyl BTBT LC semiconductor possessing fluorine substituted pheny group, 2-dodecyl -7-(3,4-difluoro-phenyl)-[1]benzothieno[3,2-b][1]benzothiophene (2FPh-BTBT-C12) was studied on charge carrier mobility by time-of-flight (TOF) method correlated to the mesomorphism. 2FPh-BTBT-C12 exhibits highly ordered smectic mesophases with the temperature range from 175 °C to 264 °C. The introduction of 3,4-difluorophenyl group on BTBT core part leads a wide mesophase temperature range.

Liquid crystal (LC) phases formed by rod-like molecules have been extensively studied both theoretically and experimentally. Since the initial theoretical approach in 1950s, it has been shown that systems of hard rod-like particles give rise to the most common liquid crystal sequence of nematic―smectic―columnar phases based on computer simulations. On the experimental side, we recently reported that the predicted LC phase sequence has been successfully reproduced in the thermotropic LC system of the carefully prepared polysilane with an exquisitely narrow molecular weight distribution. In this work, we performed the modification of Si-H end groups of polysilane with a fluorescent dye, and observed the segregation of the dye in between the smectic layers with atomic force microscopy (AFM) and scanning near-field optical microscopy (SNOM).

Precise molecular orientation in polymer films enables to yield the wide variety of functionalities such as mechanical, optical or electrical properties. Generally, such polymer films are easily fabricated with the assistance of an alignment layer typically processed by external stimuli: mechanical stress or irradiation with polarized light. In this study, we directly fabricated polymer films having macroscopic and precise molecular orientation in one or two dimensions simply by photopolymerization with the spatial gradient of light intensity. The photopolymerization generates molecular diffusion and flow providing orientation of anisotropic molecules without either an alignment layer or polarized light.

Nematic liquid crystals (N) are known to transform to chiral nematic liquid crystals (N*) on doping a small amount of chiral molecules, whereas the induction mechanism is still not fully understood. We investigate the effect of dipolar interactions between dopants and liquid crystals using ruthenium complex dopants with Δ, Λ chirality. We prepared four different dopants by changing the number and position of bromine atom introduced to the ligand. Depending on the position of the bromine atoms, N* with opposite helices were selectively formed on doping with MBBA and 5CB.

Azobenzene containing (PAz) and cyanobiphenyl containing (PCB) polymethacrylates exhibit homeotropic and random planar orientation in thin films, respectively. Blended films were prepared from these polymers (PCBMA:PAz

We have studied liquid-crystalline (LC) multifunctionalized semiconductors. We have already reported LC perylene tetracarboxylic bisimide (PTCBI) derivatives bearing oligosiloxane chains and a triethylene oxide chain complexing with metal ions. These LC compounds exhibit nanosegregated smectic phases in which ion- and electron-conductive layers are integrated separately. In this study, LC PTCBI derivatives bearing polymerizable cyclotetrasiloxane rings are synthesized in order to produce insoluble polymerized films which can conduct electrons as well as ions. This compound exhibits a smectic phase at room temperature, and X-ray diffraction measurement indicates interdigitation between triethylene oxide chains which form ion-conductive sublayers. The spin-coated thin films are polymerized by the exposure to acid vapors to be insolubilized.

ermal Conductivities (TCs) and Thermal diffusivities (TDs) of side–chain PmBEn polymer smectic (Sm) Liquid Crystals (LCs) were measured by thermal wave analysis. TDs measured for monodomain SmA1 LCs of PmBE1 are greater TDs in the LC director direction than in the transverse direction. The TD in the director direction increases with number of spacer methylene units (m) being greater for odd-m PmBE1 as back bones are confined more closely between side-chain layers. When TD is compared between polydomain LCs, the SmA1 LCs have greater TD than the SmAd LCs of PmBEn with n≧4 of the same degree of backbone confinement. These trends in the TDs of side-chain polymer Sm LCs are explained if the LCs have thermal resistances in backbones and in overlap of alkyl tails.

We synthesized novel rod-like liquid-crystalline mechanochromic (MCL) compounds and explored their properties. Novel benzonitrile terminated compound shows blue luminescent in initial state, and the color is changed to yellow by grinding. We also prepared MCL-dispersed film by using polymethyl methacrylate and succeed in patterning of mechanoinduced color change.

We prepared an amorphous blue phase (BPIII) material consisting of a nematic mixture, a chiral compound, a binary monomer mixture and a photo-initiator. The BPIII material was photopolymerized, and the remaining liquid crystal was removed to create a porous cast. By refilling the cast with the achiral nematic mixture, we obtained a polymer-templated BPIII (TN–BPIII). The temperature range of BPIII was extended to more than 80 K. The Iso–BPIII transition temperature was found to depend on Iso–N temperature for the used achiral nematic mixture. We compare electro-optical properties of the TN–BPIII to those of the corresponding polymer-stabilized BPIII (PS–BPIII).

Flexible liquid crystal displays (LCDs) are required to keep the cell thickness in a curved state. The polymer walls structure fabricated by the photo-polymerization of monomer materials using a pattern UV irradiation has been proposed to stabilize the cell thickness. However, the pattern UV irradiation using photo-mask has a problem of UV light leakage to the pixel area and degrade the image quality of flexible LCDs. In this study, we have investigated the separation of the polymer walls and liquid crystals by controlling a wettability on the substrate surface instead of the pattern UV irradiation using a photo-mask.

In this study we examine a newly proposed polymer-sustained LC alignment method in order to control arbitrarily the LC alignment. The method is based on the concurrent use of SiO2 nanoparticles whose surface is covered with UV curable functional group such as methacrylic one, which are embedded into the alignment layer of polyimide, and UV curable LC monomers added to a LC host material. We found that such kind of functionalized nanoparticles helps to form polymer network selectively at LC-alignment layer interface even at low concentration of UV curable LC monomers, leading to a change in pretilt angles.

Photoalignment of liquid crystal copolymer films with N-benzylidenaniline and biphenyl with different terminal substituent are explored. Control of in-plane and out-of-plane orientation in liquid crystalline polymeric films, which is thermally induced out-of-plane, was investigated by coating low molecular compounds. Furthermore microscopic 3D orientation films are fabricated by coating low molecular compounds by use of inkjet.

Liquid crystalline polymers (LCPs) with N-benzylideneaniline (NBA) side groups containing fluorine are synthesized by in-situ reaction of polymethacrylate with benzaldehyde side groups and phenylamine monomeric derivatives with fluorine in the film. Inkjet coating of phenylamine derivative achieves patterned photoinduced orientation of the resultant films.

Facile fabrication of a photoalignment film of non-photoreactive liquid crystalline (LC) polymer comprised of benzoic acid (BA) side groups (PBA) by top-coating of photoreactive cinnamic acid (CA) monomer via H-bonds between PBA and CA is investigated. Linearly polarized ultraviolet (LPUV) light irradiated to top-coating film generates an axis-selective photoreaction of CA, and molecular reorientation is induced by subsequent thermal treatment at LC temperature. H-bond formation between PBA-CA plays an important role in the effective photoinduced reorientation of BA side group.

Liquid-crystal cylindrical-lens-array (LC-CLA) having two pairs of slit-patterned electrodes was studied as a device to control light distribution properties. The LC-CLA has a pair of separated two circuit to drive independently, that can work as light deflection and diffusion. In the experiment using LED light with stacking two LC-CLA (each LC thickness: 80um), the light deflection angle of 26 degrees were obtained by same driving condition for both. While, the diffusion state of ± 26 degrees were obtained by driving in opposite direction. By the conventional step switching method, rising time is 7 seconds and recovery time is 13 seconds. We succeeded to make those response times less than one-tenth, introducing over-drive-pulse and reset-pulse at switching of turn on and off, respectively.

Liquid crystals (LCs) possess great potential for tunable optical elements such as lenses and deflectors. We have recently developed a novel LC lens device based on a Fresnel structure. In these devices, high-resistivity and insulating thin films are placed such that a saw-tooth distribution of voltage is formed in the LC layer. In this study, we numerically analyze the reorientation of the LC director and the resulting optical phase retardation in Fresnel-type and standard-type LC lenses, and compare their performance. In particular, we consider the molecular twist induced in the LC layer by the in-plane component of the voltage distribution, and investigate its dependence on the device structure.

Since ferroelectric liquid crystals (FLCs) show a fast response to electric field, they are highly expected to be applicable in the photorefractive (PR) effect and optical devices.We synthesized a novel chiral dopant “COOT3-88” that bears a strong chiral isosorbide-core and a photoconductive tertiophene moiety. Our test with a nematic host LC (7OCB) has shown that depending on the temperature, COOT3-88 has a very strong helical twisting power (HTP) of 80~100 μm-1, as expected for an axial chirality. The spontaneous polarization in the FLCs induced by COOT3-88 and the photorefractive effect using COOT3-88 are under investigation.

Recently, liquid crystals have attracted much attention towards applications for dimming materials because it has large refractive index anisotropy and its molecular orientation can be controlled by an external stimulus, such as electricity and light. In structurally anisotropic dye doped systems, molecular interactions between the liquid crystal molecules and the dye molecule excited at high light intensity cause the molecular reorientation above a light-intensity threshold. In recent years, we have found that the threshold intensity of molecular reorientation is greatly reduced by adding a polymer to the dye-doped liquid crystal. In this study, we fabricated a polymer network dye-doped liquid crystal (PNLC) films in which polymer main chain was crosslinked, and studied molecular reorientation behavior and optical power limiting behavior based on molecular orientation changes in the PNLC films.

Liquid-crystalline (LC) system doped with dye molecules exhibits significantly enhancedphotoinduced reorientation behavior compared to undoped LC system. Recently, we reported thatgreen fluorescent coumarin dyes act as triggers for photoinduced reorientation of nematic LCs toreduce photothermal effect during photo irradiation at high-light intensity. In this study we exploredphoto responsive behavior of nematic LCs containing orange and red-fluorescent dyes to createphoto alignment systems with sensitivity in the long-wavelength region.

A photoconductive chiral dopant which posseses a chiral part at the both end of the mesogen was synthesized. The photoconductive chiral dopants were mixed with liquid crystals and their photorefractive properties were investigated. The FLC blend with double chiral dopants exhibited large ferroelectricity even at a low concentration. The photorefractive properties of these samples were examined by two beam coupling experiment.

Cholesteric blue phases (BPs) are liquid crystalline phases which form three-dimensional periodic structures. They are composed of a cylindrical substructure within which the liquid crystal director is doubly twisted; the double twist cylinders (DTCs) stack and form a lattice with either a body-centered cubic symmetry (BP I), or simple cubic symmetry (BP II). We have previously reported that transmission electron microscopy (TEM) can be a powerful tool to observe BPs in real space, but observation was limited to the (100) plane of the BP crystals. Here, we report real space observation of the (110) plane of BP crystals.

Effects of the preference to non-parallel alignment of neighboring molecules are examined within a mean-filed spirit. A conceptual phase diagram is proposed and discussed in relation to chiral liquids consisting of achiral molecules and cubic liquid crystals. A molecular factor that favors the gyroid phase is identified.

The urea derivatives possessing two or three urea moieties in them were designed and synthesized. Their phase transitions were measured by polarized light optical microscopy and differential scanning calorimetry. In X-ray diffraction measurement, some of the compounds showed rectangular columnar phases were observed. To confirm its ferroelectricity, optoelectronic studies and SHG experiments were carried out. Compound 1 with two urea units showed partial retention of the polarity and the mechanism for the ferroelectric behavior was estimated.

4-Perfluoroalkylbutoxybenzene derivatives 1(n) and 2(n) have been prepared as a new class of thermotropic liquid crystalline organogelators incorporating a perfluoroalkyl group without hydrogen bonding group. Compounds 1(n) exhibit smectic phases, on the other hand, compounds 2(n) are non-mesogenic. Interestingly, compounds 1(n) act as efficient and rapid phase-selective gelators at room temperature, while compounds 2(n) do not. These results suggest that π-π interaction is indispensable for molecular assembled system as well as fluorophilic/fluorophobic ones.

It was reported that the anomalous softening of elasticity occurs in the two-component mixture that consists of a chiral monomer and a ‘twin’ containing two repeat units of the first molecule connected by a linear hydrocarbon spacer. However, the origin of the softening is still unknown. In order to reveal what induces this drastic softening of smectic layers, we prepared some kinds of mixtures containing monomeric and twin liquid crystals, and carried out viscoelastic and XRD measurements. From these measurements, it is indicated that the softening of elasticity occurs universally in monomer-twin mixtures, but the degrees of softening widely vary by mixtures.

A cholesteric blue phase in the polymer-stabilized blue phase (PSBP) is thermodynamically stabilized by a polymer network (PN) which is formed by in-situ photopolymerization with monofunctional and bifunctional monomers. The PSBP is expected to be applied to next-generation liquid crystal displays because of its optical isotropy and fast response. The electro-optical properties and stabilities of PSBP are known to depend strongly on the structure of PN. In this study, we investigated the effect of monomer chemical structure on the properties of PSBP. In the case of using bifunctional monomer with alkyl spacer in the mesogenic core unit, the stability of PSBP was sufficiently improved and the operating voltage was successfully reduced due to a decrease of anchoring between PN and liquid crystal molecule.

Topological defects in liquid crystal (LC) are generated where the orientation of the director is discontinuous. Defects in LC possess attractive features such as the ability to trap and transport micro-sized colloids. Recently, we have demonstrated that the shapes of defects lines can be controlled by orientational easy axis patterns imprinted on the substrates. However, the orientational easy axis patterns used in the previous study limited the achievable defect shapes to circles and spirals. Here, we demonstrate that elliptical defect lines with controllable ellipticity can be generated by a simple design of the easy axis distribution.

Here, we present a real-time filming of adsorption/desorption processes of an interface-localized azobenzene-containing liquid crystal dendrimer clusters upon the EZ-isomerization process, as clarified by an unconventional video-rate atomic force microscopy. With the aid of UV-VIS absorption and grazing-incident x-ray diffraction measurements, we could gain insights on how the dendrimers develop/degenerate mesoscopic structures on surfaces upon light stimulation, i.e., a reversible wetting transitionbetweencomplete-and partial-wettingstatestriggeredbyphotoisomerization.

Effects of chemical structures of constituent molecules (azobenzene derivative and host LC compound) on light-induced liquid crystalline phase transition from 1D-organized smectic C (SmC) to the 3D-organized bicontinuous cubic (Cubbi) phases have been studied. We synthesized new azobenzene derivatives having different ester moieties (methyl, ethyl and phenyl). It was revealed that combination of the host LC (ANBC or ACBC) and the azobenzene derivatives provides a profound effect on the light-induced transition behavior for the binary systems.

Recently, we achieved the UV-induced liquid crystalline phase transition from 1D-organized smectic C (SmC) to the 3D-organized bicontinuous cubic (Cubbi) phase utilizing the photoisomerization of an azobenzene derivative. The sample is a binary mixture containing 4´-n-docosyloxy-3´-nitrobiphenyl-4-carboxylic acid (ANBC-22) and azobenzene derivative 4-(4´-n-docosyloxyphenyl-azo)benzoic acid ethyl ester (azo-COOEt-22). In this work, we investigated effects of the chemical structure and concentration of azobenezene derivative and temperature on the phase transition rate using time-resolved measurements of grazing-incidence X-ray diffraction (GI-XRD) and birefringence.

Ultra-thin smectic shells exhibiting interference color were prepared from a smectic bubble in water. In case of the fabrication of smectic shell by microfluidics method, it is generally made of nematic or isotropic phase' state of liquid crystals, but our technique enables us to make smectic shell directly. The thin smectic shell shows interference color at the edge of the shell, and the shell thickness was quantitatively determined by spectrometry. As a result, it was found that thickness of obtained smectic shells are order of several hundreds of nanometer.