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Photopolymerization of Langmuir monolayers composed of bifunctional acrylic liquid crystalline (LC) compounds was observed in situ by polarizing optical microscopy. In a dark state, monolayers of the LC compounds formed at an air-water or liquid-liquid interface exhibited liquid-like fluidity and in-plane optical anisotropy because of the coherent molecular tilt from the surface normal. Irradiated by UV light, the in-plane anisotropy and the liquid fluidity gradually disappeared with time, indicating the formation of the polymerized monolayers. Because the constituent molecules possess polymerizable acryloyl groups, under UV light, they are combined by acrylic polymer chains grown on the interface, which decreases the intermolecular distance and disturbs the coherent molecular tilt, resulting in the evanescence of the in-plane optical anisotropy and the fluidity. In contrast to the classical model of radical polymerization, the time taken for the monolayers to be photopolymerized was inversely proportional to the UV intensity, which is ascribed to the ideal two dimensionality of the reaction field. Because the polymerization degree is quantitatively estimated from the in-plane optical anisotropy of the LC monolayers, the process is traced, from moment to moment, by in situ microscopy observation.

Organic light-emitting diode displays have a cathode composed of a layer of highly reflective metal. Reflection of external light from this layer can be suppressed with a broadband quarter-wave plate. Although various types of quarter-wave plate retardation films have been prepared by copolymerizing, mixing, or laminating multiple polymers, ideal wavelength dispersion has not been achieved with thin retardation films because of their relatively low birefringence and the complexity of the procedure required manufacturing them. In this study, we developed (i) new liquid-crystalline monomers with negative wavelength dispersion birefringence that we used to obtain thin, single-layered retardation films suitable for coating and (ii) retardation films with different molecular alignments. We found that the monomers showed high solubility and high regularity of molecular alignment, with less damage to the substrate and alignment films. We also investigated the wavelength dispersion and thermal stability of the films. We succeeded in developing retardation films that had a homeotropic alignment or a hybrid alignment with negative wavelength dispersion. These alignments can be used to obtain antireflection films with an improved viewing angle for organic light-emitting diode displays or next-generation thin displays.

"Ferroelectric smectic (SmC) phase" Anchoring effects on the polymer films in the liquid crystal (LC) display devices plays key role to create the restoring force to the black state for any types of display modes, such as IPS, STN, VA and OCB etc. On the contrary, we have designed the slippery interfaces in the homeotropic ferroelectric (SmC*) liquid crystals for the DH-FLC mode as walls wetted on the electrodes in the in-plane switching cell, and success to reduce the driving voltage keeping the ultra-fast response. "Principle & Design" We have invented the new principle to produce the slippery interfaces on the glass plates or even nano-interfaces embedded in the materials such as PSChBP. Slippery interfaces are created by the disorder effect induced by the several types of frustration. For example, the impurities with surface affinity weaken or melt the liquid crystalline (LC) order near the interfaces, then boundary region of LC spontaneously play roles on the slippery interfaces. Therefore, the anchoring effect disappears, and molecular motion is lubricated by the slippery interfaces. Especially, change of the anchoring to the slippery condition can be controlled by UV illumination on localized azo dye surfaces. "Evaluation" We measure the dynamics of surface director rotation under rotating magnetic field, and analyze the response of the surface director by changing the strength of the magnetic field and rotation speed of the cell. Therefore, we correctly evaluate the change of the anchoring condition which is related to the anchoring energy and viscosity of surface director. Anchoring phenomena is strongly dependent on the model of the slippery interface, the temperature and even the LC materials on the interface.

Azobenzene liquid crystals, possessing two chiral moieties at both of the peripheral ends of the molecular structure, show characteristic chirality-originated liquid-crystalline and physical properties: emergence of stable smectic Q phases, a photoinduced phase transition between 3D liquid crystal phases, and induction of birefringence in the “liquid” phase. A dichiral compound, of which rigidity of the core is reduced by the introduction of ester groups, showed no smectic Q phases, but exhibited the antiferroelectric smectic C phase. The “liquid” phase of the less-rigid azo-compound was found to show electrically induced birefringence.

We studied the hyper-swollen behavior of a perfluorinated smectic liquid crystal, 11-(4′-cyanobiphenyl-4-yloxy)undecyl pentadecafluorooctanoate (BI), through addition of perfluorinated oils. The studied compound, BI, has a bilayer SmA–SmC phase sequence due to microphase separation of hydrocarbon chains and perfluorinated chains. We found that BI can be diluted with straight-chain, soft perfluorinated oils and that the repeat distance of the smectic layer can be greatly swollen to about three times thicker than that of pure BI. However, there was no clear physical mechanism for the long-range interlayer repulsive forces, such as the electrostatic force, observed in the lyotropic system. Furthermore, we found that interlayer tilting can be propagated along the smectic layers in the SmC phase even in the hyper-swollen state, despite insertion of thick liquid layers of perfluorinated oil between the smectic layers of BI. The orientation of the intercalated perfluorinated oils was also discussed based on the conoscope observation.

We designed the fast switching & low driving voltage principle with nano slippery interfaces in nematic gels. Confinement effect by the gel network can accelerate the response time of nematic due the localization of director motion as similar way to the cholesteric blue phase. However, the anchoring of the director on the gel network induces the driving voltage. Slippery effect on the nano interface of the gel network can reduce the driving voltage due to the lubrication of the director motion. Since azo dye acrylates are co-polymerized with nematic gels (Azo-NGel), we can demonstrate the UV-switchable nano-slippery interface on the nematic gels. Dynamic Light Scattering (DLS) provides us the information of the dynamics of director rotation. Dispersion relation of the pure 7CB-T15 mixture completely satisfies the prediction of hydrodynamic modes in the nematic. On the contrary, the relaxation frequency of the Azo-NGel keeps fast response in the low wave-number region due to the confinement effect. Electro-Optic response (EO) of the Azo-Ngel without UV illumination shows the serious increase of the driving voltage compared to the pure 7CB-T15 mixture. When the Azo-Ngel is illuminated by UV-light Slippery interfaces can be created by the trans-cis isomerization of the Azo dye of the side-chain on the nano network of nematic gels. EO under UV illumination shows the drastic reduction of the driving voltage keeping the fast response time. We have also confirmed that the dispersion relation of the UV illuminated Azo-Ngel is almost the same as that of Azo-Ngel without UV illumination by the DLS measurement. Thus, the confinement effect for the nematic gels is still effective after the slippery interface is created by the UV illumination. We success to demonstrates that the acceleration of the response time is compatible with reduction of the driving voltage by the localization and lubrication of director motions due to the design of the nano-slippery interfaces in the nematic gels.

Anchoring effects on the polymer films in the liquid crystal (LC) display devices plays key role to create the restoring force to the black state. However, the chiral materials with spontaneous helix, such as deformed helix mode in SmC* (DH-FLC) or the polymer stabilized blue phase (PSChBP), can recover black state by rewinding motion of the helix itself. We have invented the principle and design of slippery interfaces, which has zero anchoring force for attached LC molecules on the interfaces, and confirmed the drastic reduction of driving voltage in DH-FLC mode of SmC* (

We present two types of novel side-chain photo-polymers with cinnamoyl moieties for photo-alignment and patterning of the alignment of liquid crystal displays (LCDs). One type is designed for photo-thermal processing; the other comprises co-polymer side-chain functions combining room temperature photo-processing with excellent image sticking. The planar aligning materials are highly UV sensitive (315nm, 150mJ/cm2). They target in-plane switched (IPS)-LCDs with excellent AC-image sticking, comparable to brushed polyimides. Correlations between photo-dimerization and image sticking are discussed.

The structure–property correlation has been systematically investigated by the modification of the central core part of the dichiral materials so that the chiral and/or non-chiral issue having an effect on the formation of the layered or inter-connected structure can be studied. The central phenyl core of the dichiral compound showing the inter-connected ordered smectic Q phase has been modified in the following three ways: introduction of the substituent in the central phenyl core, introduction of the alkyl spacers between the central phenyl core and the peripheral mesogenic groups, and replacement of the central phenyl ring by the alkyl spacer. It has been found that (1) a symmetric structure stabilizes the tilted molecular ordering and the inter-connected structure, whereas the non-symmetric structure stabilizes the smectic A ordering; (2) a flexible molecular structure stabilizes the layered phase rather than the inter-connected; (3) increase in the degree of the segregation in the molecular assemblie...

Pre-organization effects are investigated for the laterally-connected liquid crystals possessing a biphenyl connecting group. The homeotropic texture of the N phase of a free-standing film sample was found to change into the other “Schlieren” texture on cooling even in the N phase, which then changes into the “Schlieren” texture of the SmC phase on further cooling. The possibility of the emergence of biaxiality in the N phase is discussed.

We investigated the swelling effect in the thermotropic smectic C liquid crystal phase by dilution of the solvent. We found that the twist elastic constant monotonically decreases with increasing swelling ratio, eventually becoming an order of magnitude smaller than its original value at the swelling limit. Our conclusion is that intercalated solvent molecules prevent direct collisions between liquid crystal molecules, which weakens the steric interaction to produce the orientation order across the smectic layers. This is the main mechanism for the softening of the twist elastic constant upon swelling.

The effect of chirality on the liquid crystal organization has been systematically investigated between (S,S)- and (R,R)-isomers of a dichiral azobenzene compound. The racemic mixture was found to show the cubic phase (Im3m), indicating that the studied compound shows the cubic structure without the effect of chirality. However, with increasing optical purity of the racemic mixture, the cubic (Im3m) structure changes into the tetragonal phases (I422 and I4(1)22), which have been known as the SmQ phases, via a chiral cubic phase (I432). This is the first example of "chirality-driven" cubic-tetragonal structural change observed in liquid crystal systems, which is experimental evidence showing the novel type of chiral effect that produces the anisotropy in the structures of soft materials. The emergence of the anisotropy, i.e., the cubic-tetragonal phase transformation, is also induced by means of photoinduced phase transition of the SmQ phases based on cis-trans photoisomerization of the azobenzene compounds.

Liquid-crystalline smectic phases possess a layered structure which is so soft that the structure sometimes deforms and changes into a three dimensional ordered or disordered inter-connected structure. The “sponge” is a disordered phase, whereas the “smectic Q” is an ordered one, both of which were found to appear in highly chiral thermotropic systems. The structures and properties of the sponge phase were investigated by the microscopic, X-ray diffraction and visco-elastic measurements and the soft nature of the phase is confirmed. Both of the phases are produced only if the optical purity of the compound is high enough, in which the stability of the smectic Q phase was found to be more sensitive to the optical purity than that of the sponge phase.

We investigated liquid-crystalline properties and photoresponse of a chiral azobenzene compound and found that it shows two kinds of highly-ordered liquid crystal phases. Studies on the optical textures and thermodynamic properties of the azobenzene compound suggest that the both mesophases are classified as the smectic Q (SmQ) phase which has been known as one of the chirality-induced three-dimensional (3D) liquid crystal phases. By the miscibility studies, one of the mesophases was confirmed to be T*I structure among the four structures of the SmQ phase. In a spectroscopic study of the chiral azobenzene compound in a tetrahydrofuran solution, it has been confirmed that a cis-trans photoisomerization can be induced by irradiation with ultra-violet light. Although the 3D structures are not sensitive to the applied electric field, we successfully demonstrate the “photo-switching” of these 3D structures by means of the photoisomerization.

An antiferroelectric liquid crystal (AFLC) with dimeric molecules which take a bent molecular structure may show the nematic (N) phase. However, it has not been obvious yet why the antiferroelectric chiral SmC (SmC* A ) and N phases may coexist in the phase sequences of the dimeric AFLC. In this study, the molecular alignment structure of both liquid-crystalline phases has been researched in detail with a polarized Fourier transform infrared spectroscopy (FT-IR). In 8PY11OCB, the directors of both mesogenic moieties are oriented to the rubbing direction due to high thermal motion in the N and SmA phases, that is the molecular shape is almost rod like. In the SmC A phase, a herringbone alignment of the mesogenic moieties appears because the bent molecular structure becomes stable due to lower thermal motion. In the case of OBnCB, we obtain also almost the same results and discussion.

By doping photo-curable monomers showing properties of a low driving voltage into FLC media and performing an appropriate photo-curing, we succeeded in fabricating novel Polymer-stabilized FLCDs exhibiting V shaped switching (PSV-FLCDs) with τ = 100 μs to 200 μs and with a free from the temperature dependence of operating voltage within 3 mV/°C in the range from −5°C to 50°C. We also demonstrate a field sequential full color LCD with 4 inch diagonal and 254 ppi that is capable of displaying moving images without blurring and break.

“Isotropic order”. Soft condensed matter system can form the huge length scale order. SmBPIso is characterized by the simultaneous presence of the local order parameter of an helix and of a smectic layer, while being spontaneously isotropic without any characteristic discontinuity on a mesoscopic length scale. It is great advantage for the optical devices that the spectrum of the iridescent color of SmBPIso is completely equivalent by the changing the viewing angle because of the special isotropic symmetry and its wavelength can be successively controlled by changing temperature. Recently, we found the color can be tuned by shining the strong pulsed laser light. Then we can artificially design the special pattern of the “structural color” by scanning and on/off the laser light beam. Response time of the color shift is not so fast but not so slow (~200msec) in spite of the existence of the complicated inter-connected multi-lamellar structure. We also confirms experimentally that the existence of the collective fluctuation mode just around the sub second by the dynamic light scattering measurement. Relaxation time can be assigned as reorientation motion of the helical pitch, which must be correlated to the dynamics of the shrinkage/elongation of the inter-connected multi-lamellar structure through the coupling between two types of the liquid crystalline orders. Furthermore, we found that cubic SmBP reenter the SmBPIso at super cooling temperature (Tsc) in the twin poor region. Since Smectic A phase appear by applying the heating shock and is stable until Tsc where cubic SmBP reappear. So we can conclude that the re-entrant SmBPIso is super-cooled state. We also found the power law slow dynamics in the director orientation fluctuation as similar to the conven smectic-A phase, which is hidden by the super cooling of SmBP tional liquid-glass transition. However, it should be noted that

Liquid crystal is a representative soft matter, which has physical properties between those of conventional liquid and those of crystal in a temperature range above a melting point. A liquid-crystal display (LCD) employs the response of the liquid-crystal alignment to the electric field and is a key device of an information display. For common LCDs, the precise control of the initial alignment of LC molecules is needed so that a good dark state, thus a high contrast ratio, can be obtained. If the birefringence can be induced in the liquid phase by the application of electric field, it is of great use as a material for the LCD application. In this study, we will report a unique property of dichiral azobenzene liquid crystals: an electric induction of birefringence in a liquid phase of an antiferroelectric dichiral azobenzene liquid crystal. The optically isotropic texture changes into the homogenous birefringent texture by the application of the in-plane electric field above the clearing temperature of the liquid crystal. We find that one of the possible reasons of the induction of the birefringence in the isotropic phase is the electrically-induced increase of the phase transition temperature between the antiferroelectric liquid-crystalline and “liquid” phases, i.e., increase in the clearing temperature. The resulting birefringence can be disappeared by the irradiation of UV light, due to the photoinduced isomerization of the azobenzene compound, thus dual control of the birefringent structure, by the irradiation of light and/or by the application of the electric field, is achieved.

Electrically tunable binary liquid crystal (LC) diffraction grating has been designed and fabricated in a simple technique using an LC composite containing photo-curable LC pre-polymer. The binary grating consists of alternating stripes of homeotropic monodomain and non-aligned multidomain. The diffraction efficiency can be modulated by an applied electric field, and is independent of the polarization of incident light.

We prepared a homologous series of dimeric liquid crystals, α‐(4‐cyanobiphenyl‐4′‐yloxy)‐ω‐[4‐(5‐alkylpyrimidine‐2‐yl)phenyloxy]alkanes (mPYnOCB), in which cyanobiphenyl and phenylpyrimidine moieties are connected via a flexible central spacer. We investigated the physical properties of mPYnOCB and of binary mixtures between the dimeric compounds. The interdigitated anticlinic smectic C (SmCanti) phase was found to be induced for some binary mixtures between the dimers with a different odd‐numbered spacer. Furthermore, a striped pattern was observed in the SmCanti phase of a homeotropically aligned sample. The striped pattern was propagated when the temperature of the sample was varied. We discuss the correlation between the structure of the SmCanti phase and the appearance of the striped pattern.

Molecular design producing a strong chiral effect has been proposed and dichiral twin and monomeric materials have been prepared systematically based on this concept. A variety of superstructures are generated in the chiral smectic phases, including ferrielectric and antiferroelectric phases, a twist grain boundary phase and the variants, such as smectic blue and smectic Q phases, and mysterious isotropic phases exhibiting an anomalous electric-field induced phase transition.

A homologous series of novel λ-shaped mesogenic compounds in which three mesogenic groups are connected to 3, 4-dihydroxybenzoic acid has been prepared and their physical properties investigated by means of optical microscopy, differential scanning calorimetry and X-ray diffraction measurements. The λ-shaped compounds studied showed unusual smectic phases. 4-Cyanobiphenyl-4′-yl 3,4-bis{6-[4-(5-octylpyrimidin-2-yl)phenyloxy]hexyloxy}benzoate was found to realize an incommensurate SmA (SmAinc) phase. A “uniform planarly” aligned sample of 2-(4-octylphenyl)pyrimidin-5-yl 3,4-bis{6-[4-(5-octylpyrimidin-2-yl)phenyloxy]hexyloxy} benzoate showed a Schlieren-like texture in the smectic phase. We discuss structural effects of the λ-shaped compounds on molecular organization in liquid-crystalline phases.

Novel symmetric and non-symmetric chiral twin compounds possessing one or two thioether groups in a central spacer were prepared, and the effect of substituting oxygen for sulphur on the liquid crystalline properties investigated. Chiral twin compounds possessing an alkylsulphanyl spacer showed an antiferroelectric phase exclusively. However, replacing the alkyloxy chain of the analogous monomer by the alkylsulphanyl chain has no significant effect on the phase transition behaviour, i.e. both of the monomers showed the ferro- and ferri-electric phases as well as the antiferroelectric phase. Thus, different effects of introducing the thioether linkage were for the first time observed between twin and monomeric systems. The introduction of oxygen or sulphur atoms into the central alkyl spacer of the chiral twin was also investigated, and these modifications were found to stabilize the SmA phase. Furthermore, the twin compound possessing a thiaalkyl spacer showed two different molecular assemblies in the sme...

In smectic liquid crystals (SmLCs) having no nematic (N) phase in the phase sequence, such as antiferroelectric SmLCs and SmLCs with V-shaped electrooptical switching, it is hard to obtain the LC media which have a uniform molecular alignment structure. This is because the transition of isotropic (Iso) phase directly to Sm phase during the cooling gives rise to a non-uniform Sm layer structure due to the both occurance of molecular alignment and Sm layer formation at the same time. We propose an idea to fabricate defect-free SmLC cells in which the uniform Sm layer structure is realized by the use of an intervening surfacial LC layer with Iso-N-Sm (INS) phase sequence.

A hybrid surface-stabilized ferroelectric liquid crystal (SSFLC) having an intervening interfacial layer with a graded transition temperature is determined to be successful for preventing the structural transformation from C1 to C2 chevrons during the cooling process. As a result, a zigzag defect-free SSFLC medium with C1 structure can be obtained. A hybrid SSFLC fabricated by deliberately lowering the SmA-SmC phase transition, temperature (TAG) in the surface region takes C1-uniform structure, and on the other hand, a hybrid SSFLC having a surface layer with TAC higher than the bulk region prefers twisted orientation to uniform. The C1-twist structure of the layer hybrid SSFLC is caused by the suppression of C1-C2 structural transformation in the surface region due to the bulk region with lower TAC and the easy formation of electrical coupling between the FLC dipole and the substance surface because the bulk region still takes the SmA phase just after the SmA-SmC transition of the surface region.

In this work, a novel surface functionalized SiO2-supported Ziegler-Natta catalyst was developed for ethylene polymerization. A state-of-the-art control of some unique characteristic catalytic properties on the surface functionalized SiO2-supported catalyst analogized from the previously reported poly[propylene-co-(7-methyl-1,6-octadiene)]-supported Ziegler-Natta catalyst had been successfully realized through a precise molecular level catalyst design on the silica gel surface functionalized with linear long alkene chains through the reaction between unsaturated alcohol 9-decene-1-ol and hydroxyl groups on the silica surface. The active sites of this SiO2-supported catalyst prepared in this study showed very stable activity without obvious deactivation for more than 50 h and the molecular weight distribution of polyethylenes varied significantly from narrow and unimodal to broad and multimodal by solely changing the type of Al-alkyl cocatalyst from diethylaluminumchloride to triethylaluminum.

Ferroelectricity is desirable for realizing fast-response liquid crystal devices. Existing ferroelectric liquid crystals are improper with the spontaneous polarization Ps being indirectly induced by the broken centrosymmetry of molecular arrangement. We found that Langmuir monolayers of certain dialkylated nematic compound exhibit a laterally polarized two-dimensional ferroelectric nematic. The Ps is comparable to that of chiral smectic liquid crystals, and shows a fast linear electro-optic switching with a microsecond response. Estimates of electrostatic energy suggest that the ferroelectricity may be driven by the direct dipolar interactions.

The formation, variation and conversion of isospecific active sites were investigated, based on the isotacticity distribution of the polypropenes analyzed by the temperature rising elution fractionation (TREF) method. Stopped-flow polymerization of propene was carried out with a MgCl 2 -supported Ziegler catalyst in the absence or presence of an internal or external electron donor so that the effects and roles of the electron donors could be clarified. The results showed that various kinds of active sites with different isospecificities, including the highest isospecific active sites responsible for producing the highest isotactic fraction (elution temperature: > 112°C) existed, even in the electron donor-free catalyst system. The isospecificity of the active sites in the donor-free catalyst might have originated from a surface monolayer multinuclear titanium species, namely an island of titanium species. The addition of the external electron donor converted a part of the aspecific and/or low isospecific active sites into the second highest isospecific active sites, but showed no effect on the formation of the highest isospecific active sites, whereas the addition of an internal donor played an important role in creating the highest isospecific active sites as well as suppressing the formation of the aspecific active sites.

Binary mixtures between a chiral twin possessing two identical chiral moieties and the analogous parent monomeric liquid crystal were prepared, and liquid-crystalline properties investigated. TGB phase was found to be induced in some mixtures between (R, R)-twin and (R)-monomer. A mixture between (S, S)-twin and (R)-monomer showed an induced nematic phase due to the pitch compensation, however, also showed an induced TGB phase. XRD measurements showed that the intra-layer molecular distance increases by mixing the twin and monomeric compounds, which may produce a weaker layered structure, consequently, the TGB structure was stabilized.

A homologous series of chiral twin liquid crystals possessing identical chiral moieties at both peripheral ends, i.e. optically active α,ω -bis{4-[(4′-(1-methylheptyloxycarbonyl)-4-biphenylyl)oxycarbony]phenoxy}alkanes, has been prepared and their liquid crystalline properties investigated. The homologues preferred to show the ferrielectric and/or antiferroelectric phase rather than the ferroelectric phase. With ascending central spacer length, the temperature range of the ferrielectric phase became narrow and eventually disappeared for the dodecyl homologue, suggesting that the coupling in motion and/or direction between two mesogenic parts of each twin molecule has an important effect on the stabilization of the ferrielectric phase. The octyl and dodecyl homologues showed a wide temperature range chiral nematic phase (ca. 10°C or more), so that these compounds were found to be the first examples showing antiferroelectric and/or ferrielectric phases with a broad temperature range of the chiral nematic ph...

A novel strategy for preparing non-symmetric chiral twin liquid crystals was proposed, where two identical chiral moieties were designed to be located at both peripheral ends and the non-symmetric character was introduced by the non-symmetric central connecting structure. Thus, optically active chiral non-symmetric twin homologues, [4′-(1-methylheptyloxycarbonyl)-1,1′-biphenyl-4-yl] 4″″-[ω-[{4″-(1-methylheptyloxycarbonyl)-1″,1″′-biphenyl-4″′-yl}oxycarbonyl]alkyloxy]benzoate, were prepared, which were found to exhibit the antiferro-, ferri-, and ferroelectric phases. Furthermore, two more phases were observed between the ferroelectric and isotropic liquid phases. The lower-temperature phase was optically isotropic under the polarized light microscopy for both of the homogeneously and pseudo-homeotropically aligned thin samples, whereas the high-temperature phase showed a mosaic texture. Both of these anomalous phases were found to have a layered structure with a smaller layer spacing than the smectic phase. The stability of these phases was quite sensitive to the optical activity. With reduction of the optical purity, these phases disappeared but the Twist Grain Boundary phase was observed. A 1 ∶ 1 mixture of (S,S)- and (R,R)-isomers just showed the smectic A phase instead of these anomalous phases.

Additive effects of donors on the initial polymerization of 1,5-hexadiene with the MgCl2-supported Ziegler catalysts were investigated by using the stopped-flow method, temperature rising elution fractionation (TREF) analysis, and kinetic study. The cyclopolymerization of 1,5-hexadiene proceeded within an extremely short period (≤ 0.2 s) and yielded a unique poly(methylene-1,3-cyclopentane). cis ring content and cis–cis unit in meso dyad of the resulting polymer were increased by the addition of electron donors. The influence of internal and external donors was examined by the estimation of kinetic parameters and TREF analysis. Because the addition of the internal donor caused an obvious change in one of the kinetic parameters and the microstructure, an isospecific active site was considered to be formed by the addition of the internal donor. In the case of the external donor, the additive effects on the stereospecificity were weaker than those of the internal donor. It was expected from TREF measurements that the external donor modified an aspecific active site into a lower isospecific active site. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2976–2983, 2002; DOI 10.1002/app.2326

本研究では, 昇温溶離分別法 (TREF) を用いて分析したポリプロピレン (PP) の立体規則性 (イソタクチック) 分布を基に, MgCl2担持型Ziegler触媒が有するイソ特異的活性点の特性分布と内部および外部ドナーがその分布に及ぼす効果を調べた. 内部および外部ドナーを含まないMgCl2担持型Ziegler触媒系を用いた, ストップフロー法によるプロピレン重合で得られたポリマーのTREF噺から, Ti, Mg, Clのみからなる触媒からも, 高イソタクチックPPをはじめ, 異なる立体規則性をもつポリマーが得られ, 本触媒においても活性点の立体特異性に分布のあることがわかった. ドナーの添加効果に関する検討では, 内部ドナーは非立体特異的活性点の生成を抑制する効果があるのみならず, もっとも立体特異性の高い活性点の創製に重要な役割を果たしており, 一方, 外部ドナーは非立体特異的活性点をイソ特異的活性点へ変換させることはできるものの, その効果は低く, しかももっとも立体特異性の高い活性点への変換には効果をもたないことがわかった.

Chiral twin compounds, possessing two chiral moieties in such a way that the chiral centres are located at the both peripheral sides of a molecular twin structure, have been prepared and the liquid-crystalline properties investigated. The chiral twins showed stable ferrielectric and antiferroelectric phases. A twist grain boundary phase was found to appear by mixing the twin and the analogous monomer.

To investigate the role of the internal donor in a Ziegler–Natta catalyst, the nature and existing states of the internal donor were intentionally varied by alkylaluminium treatment before polymerization, and the catalytic properties during propene polymerization were accurately evaluated using the stopped-flow method. A significant decrease in the amount of the remaining internal donor was observed during the initial stage of the extraction. The polymerization results show a gradual decrease in the polymer isotacticity with an increase in the extraction time. These different patterns, as a function of the extraction time, indicate that the amount of the remaining internal donor is not directly related to the isotacticity of the produced polymer. © 2002 Society of Chemical Industry

Zigzag defects in surface-stabilized ferroelectric liquid crystals (SSFLCs) originate from the structural transformation from C1 to C2 chevrons during the cooling process. This transformation occurs so as to accommodate the increasing tilt angle of the FLC under the constraint of the surface anchoring. Based on this scenario of zigzag defect formation, we propose a new scheme to obtain defect-free SSFLCs in which the C1-C2 transformation is suppressed by the use of an interfacial layer that has a gradually decreasing SmA-SmC* transition temperature toward the substrate.

The electric-field-induced phase transition of a chiral liquid crystal containing Br revealed a transition phase between the three-layer periodicity ferrielectric phase and the synclinic ferroelectric phase in the electric field versus temperature phase diagram. Resonant x-ray scattering from the transition phase showed a diffuse streak or spotty weak reflections, which were composed of strong $m$/3-order (where $m$ = 1 and 2) reflections and other weak peaks. The spotty reflections were found to be related to a 12-layer periodicity phase with a weak contribution from the 15-layer periodicity. An x-ray intensity analysis based on the Ising model suggested that the 12-layer periodicity phase was composed of two three-layer ferrielectric blocks and six synclinic layers. This model indicated that, in the transition phase, the three-layer ferrielectric molecular configuration gradually changed to the synclinic configuration. The diffuse streak appearing around $m$/3-order reflections near the field-induced transition from the four-layer periodicity phase to the synclinic ferroelectric phase is also discussed.

This article has no abstract. Keywords: liquid crystal; blue phase; molecular design; frustration; double-twist cylinder; chirality; elasticity; biaxiality

During the development of liquid crystals there was an ongoing discussion if ferroelectricity could exist in LC materials. Until then, ferroelectricity only existed in solids with a specific crystal structure having no inversion symmetry center. Ferroelectricity was considered to be impossible in gases or liquids, but since liquid crystals have a regularity to some extent, the expression of a ferroelectric liquid in the liquid crystal was expected. In fact, there have been measurements of pulses of electric current in liquid crystals when applying the polarity inversion pulse voltage, which were similar to the currents observed in association with spontaneous polarization reversal of a ferroelectric to the liquid crystal, but this effect is not due to ferroelectricity. Meanwhile, the liquid crystal DOBAMBC showing the ferroelectric smectic C phase was reported by Meyer et al. in 1975 (J. De Phys. (Paris) 36:L-69, 1975).

In this article we report the first example of a pair of symmetrically substituted chiral twin enantiomers that exhibit stable wide temperature range ferrielectric and antiferroelectric phases, and which have large tilt angles of over 45°. In addition, both of the enantiomers exhibited an isotropic–isotropic liquid transition just above the transition to the liquid crystalline state.

Two different series of smectic liquid-crystalline biphenyl carboxylates have been prepared and their smectic properties investigated. The ‘lateral’ alkyl chain at the branching carbon was varied from methyl to hexyl for the homologous series of 4-(1-alkylheptyloxycarbonyl)phenyl 4′-octyloxybiphenyl-4-carboxylates. The antiferroelectric phase (SCA(*)) was observed for the homologous series except the pentyl homologue. The smectic layer thicknesses for the series were found to increase as ascending the ‘lateral’ alkyl chain, indicating that the ‘lateral’ alkyl group of the series is in fact along the molecular long axis to some extent, which can occur if the molecule has the ‘bent-shaped’ structure.

Helical macrostructures in the liquid-crystalline phases induced by chiral twin materials where the chiral centre was introduced at the central spacer are investigated. Relationships between molecular structures and the twisting power are reported and discussed in two different types of helical liquid-crystalline phases, i.e., the cholesteric and chiral smectic C phases.

An optically active chiral twin compound SS4 showed two novel liquid-crystalline phases. One is optically isotropic M1 phase, and the other exhibits parquet-like texture (M2 phase). Both phases changed into the antiferroelectric phase with reduction of the optical purity, showing a new type of chiral effect on the mesogenic behavior.

Optical rotation and circular dichroism measurements performed in the pretransitional isotropic region above the chiral smectic phases TGBA∗, TGBC∗, S∗C, and S∗A exhibited by 1-alkylalkyl 4′-(4″-n-alkoxyphenylpropioloyloxy)biphenyl-4-carboxylates are reported. These results revealed a high degree of increasing chiral ordering on cooling in the isotropic phase, particularly in the temperature region where a broad DSC peak appears. However, the behaviour of the pretransitional optical activity was unlike that commonly observed for chiral nematic or blue phase compounds and did not follow a simple Landau-de Gennes temperature dependence. Characteristic features of the pretransitional optical activity may aid in understanding the local structure of chiral smectic phases. Electric fields did not seem to influence the results significantly, but strong electric field-induced optical rotation behaviour was demonstrated for a mixture constituted of the laterally fluorinated propiolate ester component and ...

Ferro, ferri and antiferroelectric phases of an optically active benzoate, (R)-1-methylheptyl 4‘-(4“-n-decyloxybenzoyloxy)biphenyl-4-carboxylate, have been investigated by means of solid-state C-13 NMR and FTIR spectroscopy. Results obtained by C-13 NMR on the chemical shifts, T1 values and shapes of peaks have been reported. The shapes and intensities for the peaks corresponding to two ester groups, obtained by FTIR measurement, have also been compared between smectic phases.

Some chiral twin molecules were prepared and the structure-property relationships in the system consisting of chiral twin molecules and achiral host molecules were investigated. The spacer structure was found to have significant effect on the smectic layer strength and the twisting power in the SmC* phase. C- 13 NMR measurements revealed that a chiral twin molecule affects motion of host molecules in the SmA phase. The obtained results are discussed in comparison with our proposed model, where chiral twin molecules are intercalated in the SmC-layers formed by achiral host molecules. The chiral twin molecules may produce a strong correlation in host molecules between adjacent layer but decrease the strength of the smectic layer structure.

Spontaneous optical resolution in a racemic β-Me-TFMHPOBC molecule system was investigated with atomistic molecular dynamics (MD) simulations. Conformer distributions obtained from the MD simulations were characterized by two distinct peaks which correspond to the two oppositely directed bent conformers for each ( R , S ) and ( S , R ) enantiomer. The local enantio excess was calculated to see progression of the optical resolution from the random enantiomer distributions. In the MD simulations, however, no sign of the resolution was detected.