Publisher：Advanced Electronic Materials  

Polymer-dispersed liquid crystals (PDLCs) with nano-phase-separated structures, in which nanometer-sized liquid crystal (LC) domains are dispersed within a polymer matrix (nano-PDLCs), are transparent solid materials whose optical properties can be modulated by applying an electric field (E-field). Because the proportion of LC that can respond to an electric field is small, the specific surface area of the phase-separated interface of nano-PDLCs is larger than that of conventional PDLCs, resulting in higher drive voltages than those of conventional PDLCs. To lower the driving voltage of nano-PDLCs, highly polar LCs (C3DIO) are used with a large dielectric anisotropy (>10000), and prepared nano-PDLCs using DIO mixtures obtained by mixing them with related compounds as the host LC. Nano-PDLCs employing DIO mixtures exhibit higher E-field responsivity than those using conventional LC. In addition, the electro-optical Kerr coefficient at visible wavelength is significantly high, reaching 10−8 m V−2. Furthermore, nano-PDLCs using the DIO mixture exhibit a memory effect in which the induced birefringence remains even after the removal of the in-plane E-field. Memorized birefringence can be erased by heating or applying an E-field perpendicular to the substrate surface. Nano-PDLCs using a DIO mixture can be rewritable electro-birefringence-responsive materials that can memorize arbitrary birefringence values.

DOI： 10.1002/aelm.202400055

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Scopus

Language：Japanese   Publisher：The Japan Society of Applied Physics  

DOI： 10.11470/oubutsu.93.8_455

CiNii Research

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Journal of Physical Chemistry Letters  

The liquid crystal molecule 3-fluoro-4-(3,4,5-trifluorophenyl)phenyl 2,6-difluoro-4-(trans-5-n-propyl-1,3-dioxane-2-yl)benzoate (DIO) has attracted considerable interest owing to its unique ferroelectric nematic phase and extraordinarily high dielectric constant. To expand the DIO series, novel analogs with 1,3-dioxane units converted to ester units (EST analogs) were synthesized, and their physical properties were characterized. The EST analogs exhibited ferroelectric phases similar to those of the corresponding DIO analogs. Interestingly, an EST analogue featuring a defluorinated benzoate unit exhibited a ferroelectric smectic A phase, despite its smaller longitudinal dipole moment of 6.9 D. This result diverges from the common knowledge that the formation of large longitudinal dipoles is traditionally effective in the emergence of ferroelectric phases. Unlike the DIO series, the EST analogs can be readily obtained without the formation of undesired geometric isomers, which is advantageous for practical applications. The results of this study provide valuable insights into the design of liquid-crystalline materials expressing ferroelectric phases.

DOI： 10.1021/acs.jpclett.3c03492

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PubMed

Language：English  

DOI： 10.1093/jjco/hyad155

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PubMed

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Chemistry - A European Journal  

With the aim of controlling the orientation of liquid crystals (LCs) toward realizing external stimuli–responsive materials with tunable functionalities, we synthesized a composite of LCs and metal–organic frameworks (MOFs) by filling LCs into the pores of MOFs (LC@MOFs) for the first time. The included LCs interact with the MOFs through coordination bonds between the cyano groups of the LCs and the metal ions of the MOFs, enabling the orientation of the LC molecules inside the pores of the MOFs and the realization of birefringence of LC@MOFs. The three-dimensional nanometer interstice frameworks maintained the LC orientation even at temperatures much higher than the isotropic phase transition temperature of bulk LCs. Furthermore, the orientational state changed upon heating or cooling, inducing temperature-dependent birefringence. This study provides a new approach to the development of stimuli–responsive optical materials and stimuli–responsive MOFs.

DOI： 10.1002/chem.202303277

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PubMed

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Liquid Crystals  

Cholesteric liquid crystal (CLC) is anticipated to have applications such as blue light and ultraviolet (UV) light blocking for human skin owing to its selective wavelength reflection against incident sunlight through several hundred nanometres of a periodic helical twist structure. In this study, we investigated short chiral pitch control and enlargement of the blue phase (BP) temperature range by adding an achiral constituent of 4-n-octylbenzoic acid (8 BA) into CLC mixtures composed of three kinds of cholesteryl compounds: cholesteryl chloride, cholesteryl pelargonate and cholesteryl palmitate. Hydrogen bonding dependence of chiral pitch and BP temperature range were also investigated for achiral dopant (8 BA) and CLC mixture through temperature-dependent Fourier-transform infrared analysis. It was found that 40 wt% of 8 BA within the CLC mixture selectively reflected UV and blue light over 360–400 nm with a decrease of chiral pitch. It was also found that the BP temperature range increased by 15.6°C owing to hydrogen bond dimers composed of 8 BA molecules in the CLC mixture.

DOI： 10.1080/02678292.2023.2268041

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Scopus

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Colloids and Surfaces A: Physicochemical and Engineering Aspects  

Our earlier study showed that CaO particle gel, with loosened agglomerations of CaO particles, was generated by laser ablation of CaO powder dispersed in ethanol. We also demonstrated that porous CaO, a candidate of a low-cost and non-toxic CO2 absorbent, was obtained by simply drying the gel. For the present study, we conducted further investigation of the gelation mechanism to utilize this phenomenon as a simple and alternative preparation method of porous CaO. First, we observed the relation between the agglomeration tendency, including gelation and non-gelation, and the electrostatic interaction of CaO particles in different alcohols (methanol, ethanol, 1-propanol), because we have assumed electrostatic interaction among CaO particles as the most important factor affecting the gelation. Results showed that the agglomeration tendency of CaO particles increased with the decreasing zeta potential of CaO particles in these alcohols, which is consistent with the assumption. However, no decreased electrostatic repulsion caused by laser ablation was observed, suggesting the presence of another important factor affecting the gelation. As a possible factor, the CaO particle size composition was inferred: the colloid should contain both large particles and small particles. Interestingly, this assumption was validated by the fact that the gel was formed by mixing a raw colloid and a colloid prepared using laser ablation.

DOI： 10.1016/j.colsurfa.2023.132573

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Journal of Materials Chemistry C  

Various structured C3-DIO analogues were synthesized, and their structural and physical properties in liquid crystal phases were investigated through differential scanning calorimetry, polarization optical microscopy, dielectric relaxation, and polarization current measurements. The replacement of fluorine atoms and substitution of other polar functional groups in the C3-DIO structures significantly affected their phase transition behaviour and the emergence of the ferroelectric nematic phase. Among the analogues of C3-DIO, the dipole moments and the generation of the ferroelectric nematic phase were found to be correlated; analogs with vector-added dipole moments below 8.5 D over the whole molecular structure show only the paraelectric nematic phase, whereas those with vector-added dipole moments above 8.5 D over the whole molecular structure show the ferroelectric nematic phase. In particular, the analogue bearing a cyano group gives a large dipole moment of more than 13 D and gives rise to a dielectric constant of more than 14 000 at 100 Hz in its ferroelectric nematic state. The introduction of electron-withdrawing groups at the 4-position of the benzene ring furthest from the dioxane unit in C3-DIO is effective for the enhancement of whole dipole moments and generation of the ferroelectric nematic phase. Our results provide valuable insights into the design of DIO-based molecules with ferroelectric nematic phases.

DOI： 10.1039/d2tc05363b

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Scopus

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Applied Physics Express  

It is a significant issue in controlling the polarization distribution in ferroelectric nematic liquid crystal cells. We investigated the polarization configuration of ferroelectric nematic liquid crystals on the surface and in the bulk of parallel/anti-parallel cells with rubbed substrates and proposed the polarization models in each cell. It is found that on the surface of rubbed polyimide films, the polarization direction is fixed and opposite to the rubbing direction. Splay and twist distribution of the polarization are formed in parallel and anti-parallel cells, respectively.

DOI： 10.35848/1882-0786/acde40

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Scopus

Publisher：2023 Photonics and Electromagnetics Research Symposium, PIERS 2023 - Proceedings  

We proposed two types of LC-loaded metasurface devices having a simple cuboid and a cuboid with a chevron-waveguide structure as a unit cell and showed simulation results on light beam steering. According to the results, it has been confirmed numerically that the light steers at the metasurface devices and its angle can be controlled by change of refractive index. By employing the cuboid with a chevron-waveguide structure, the same steering angle was achieved at lower refractive index change.

DOI： 10.1109/PIERS59004.2023.10221529

Scopus

CiNii Research

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.3390/cryst11091017

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1039/d1ra03499e

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.3390/sym13050772

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.3390/polym12081625

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (scientific journal)  

Abstract: This study demonstrates a novel material design strategy to decrease the operating voltage of the polymer-stabilized blue phase (PSBP) based on intermolecular affinity between the chiral dopant and the polymer nanonetworks in the PSBP. We focus on the weak anchoring interface, the so-called “slippery interface”, at which a disordered liquid crystal or isotropic liquid layer is formed between the liquid crystal and polymer. To introduce such a slippery interface inside the PSBP, an isosorbide-based polar chiral dopant is synthesized, and this dopant is expected to show high affinity to polymers with polar substituents. The operating voltage of the PSBP with the polar chiral dopant is considerably decreased with an increasing ratio of polar substituents on the polymer, in striking contrast with the trend observed for the PSBP containing the conventional chiral dopant. Furthermore, the PSBP displays a large electro-optical Kerr constant for the PSBP containing the polar chiral dopant and polymer with the polar substituent. The experimental results suggest that the synthesized chiral dopant with a polar component acts as a chirality inducer for the BP and as a slippery interface inducer via polar-polar interaction with the polymer inside the PSBP.

DOI： 10.1038/s41428-019-0183-6

Language：English   Publishing type：Research paper (international conference proceedings)  

A calamitic liquid crystal composed of 1,3-dioxane and fluorinated aryl units exhibits a highly polar and fluid mesophase (MP phase). In the MP phase, anomalously large dielectric permittivity (ca. 10(4)), ferroelectric-like polarization switching, and second harmonic generation (SHG) are observed. SHG interferometry also indicates the polarization inversion by reversing the applied electric field in the MP phase. These experimental data clearly show that in the MP phase, a unidirectional ferroelectric-like polar order exists along the director.

DOI： 10.1117/12.2507189

Language：English   Publishing type：Research paper (scientific journal)  

The induction of chirality in a liquid crystal (LC) can lead to the development of functional LC materials with enhanced properties. A chiral dopant is known to induce a molecular rearrangement and a subsequent helical twisting in the nematic LC host, affording a cholesteric liquid crystal (CLC). However, the chirality transfer mechanism has not been fully elucidated yet. In this study, we newly synthesized 9,9′-biphenanthrene-type chiral dopants ((S)-2s) following our work on binaphthyl-type chiral dopants with the aim of unveiling the chirality transfer mechanism. The molecular structures of the chiral dopants in the crystal were determined by XRD. Significantly unique Cotton effects were observed in (S)-2s, indicating that (S)-2s adopted a different conformation in solution from the binaphthyl-type chiral dopants. Interestingly, one of the (S)-2s dopants shows positive temperature dependence of helical twisting power (HTP) though most chiral dopants show negative temperature dependence. The effects of mixing chiral dopants having opposite temperature dependence of helical twisting power were also investigated. Finally, a CLC showing temperature independency was obtained by mixing two types of chiral dopants with a reverse trend of temperature dependence in HTP.

DOI： 10.1039/c8tc05296d

Language：English   Publishing type：Research paper (scientific journal)  

Pulsed laser melting in liquids (LMLs), a convenient method of submicrometer-sized spherical particle (SMP) preparation, induces nanoparticle (NP) melting and fusion using laser irradiation at a moderate fluence for colloidal NPs. Our earlier study, conducted to produce gold SMPs (AuSMPs) from gold NPs (AuNPs) stabilized by sodium carbonate, demonstrated that the AuSMP size increased concomitantly with decreasing stabilizer concentration, although it has been suggested that laser fluence fundamentally determines the SMP size. This study elucidates an explanation of this phenomenon. Results obtained through experimentation showed the same relation when LML was conducted using AuNPs stabilized by sodium citrate. The narrower size distribution (65 ± 4 nm) of AuNPs used in this study than that of AuNPs used in earlier studies enabled us to ascertain that AuNPs smaller than the source AuNPs (approximately 10 nm diameter) are generated during laser irradiation via AuNP evaporation that occurs simultaneously with the AuNP agglomeration. A theoretical calculation predicts that the temperature increased by laser heating of AuNP depends strongly on the AuNP size, suggesting that efficiencies of stabilizer removal and agglomeration of the 10 nm AuNPs are lower than those of the source 60 nm AuNPs. For that reason, 10 nm AuNPs are likely to remain at high stabilizer concentration, leading to the formation of smaller AuSMPs because of insufficient growth. We also confirmed that such a mechanism (AuNP-size-dependent agglomeration efficiency) is applicable to improve the growth efficiency of AuSMPs on LML using AuNPs prepared by laser ablation in liquids with a wide size distribution. When smaller AuNPs were removed from the colloids by centrifugation, the amount of AuNPs remaining after LML decreased and larger AuSMPs were formed.

DOI： 10.1021/acs.jpcc.8b05911

Language：English   Publishing type：Research paper (scientific journal)  

In this study, we synthesized two novel monofunctional acrylate monomers A0DA and A3DA featuring a benzene core and a dodecyl tail, and then investigated their effect on blue phase liquid crystal (BPLC) stabilization. The benzene core is directly linked to the acrylate unit in A0DA, which forms a rigid polymeric backbone. Whereas in A3DA,a propyl spacer is employed to separate the benzene unit from the acrylate group, thereby allowing backbone mobility. By using A0DA as a monofunctional monomer in the BPLC precursor composite, stabilization of BPLC was not seen upon photopolymerization. Interestingly, the use of A3DA showed successful stabilization of BPI lattice structure after polymerization. These results confirm that the origin of stabilization effect of blue phase is the flexibility of A3DA backbone employed; therefore, the polymeric backbone flexibility is suggested to have a major influence on BP stabilization process. Furthermore, we demonstrated a low voltage electro-optical switching of PS-BPLC built on A3DA, while preserving other desirable properties of BPLC. The present study provides useful insight into monomer designs towards BPLC stabilization and enhancement of electro-optical performance.

DOI： 10.1016/j.molliq.2018.04.085

Language：English   Publishing type：Research paper (scientific journal)  

With nowadays development of cellular phones and satellite communications, liquid crystal materials have attracted considerable attention for realizing these electrically controllable microwave and milliwave components. As usual, nematic liquid crystal is mainly used for microstrip line (MSL) phase shifter, but when driving voltage is removed, the response time is very long. In this study, we discuss application of polymer stabilized nematic liquid crystals with UV polymerization for improving the response time in MSL phase shifter in which phase shift is about two times larger than that in CPW phase shifter.

DOI： 10.1002/ecj.12033

Language：English   Publishing type：Research paper (scientific journal)  

Polymer dispersed Liquid crystal (PDLC) windows are regarded as a good choice for curtain-free windows. However, conventional PDLC needs external electricity to operate, which causes extra energy consumption. These devices cannot be combined with traditional solar cells for energy savings. In this study, a new design of luminescent solar concentrator (LSC)-based PDLC device is presented. In particular, we successfully demonstrate that the PDLC can be integrated with LSC as its back scatter and potentially contributes towards the enhancement of power output by minimising backside light losses. Multi-luminophore LSC is employed to increase the absorption of air mass 1.5 solar irradiance. The edge emission measurements show multiple-luminophore-based PDLC-LSC gives the maximum edge emission power which is 1.7 times more than that of single luminophore-based PDLC-LSC device. Photocurrent measurements are also performed as an additional evidence for the improved performance of PDLC-LSC device. Finally, the visual properties of PDLC-LSC devices are evaluated to realise the compatibility of using such devices in the built environment.

DOI： 10.1080/02678292.2017.1357845

Language：English   Publishing type：Research paper (scientific journal)  

Liquid crystalline cholesteric blue phases (BPs) continue to attract interest due to their fast response times and quasi-polarization-independent phase modulation capabilities. Various approaches have recently been proposed to control the crystal orientation of BPs on substrates; however, their basic orientation properties on standard, unidirectionally orienting alignment layers have not been investigated in detail. Through analysis of the azimuthal orientation of Kossel diagrams, we study the 3D crystal orientation of a BP material - with a phase sequence of cholesteric, BP I, and BP II - on unidirectionally orienting surfaces prepared using two methods: rubbing and photoalignment. BP II grown from the isotropic phase is sensitive to surface conditions, with different crystal planes orienting on the two substrates. On the other hand, strong thermal hysteresis is observed in BPs grown through a different liquid crystal phase, implying that the preceding structure determines the orientation. More specifically, the BP II-I transition is accompanied by a rotation of the crystal such that the crystal direction defined by certain low-value Miller indices transform into different directions, and within the allowed rotations, different azimuthal configurations are obtained in the same cell depending on the thermal process. Our findings demonstrate that, for the alignment control of BPs, the thermal process is as important as the properties of the alignment layer.

DOI： 10.1088/1361-6463/aaaa4b

Language：English   Publishing type：Research paper (other academic)  

Liquid crystalline cholesteric blue phases (BPs) are of high interest for tunable electro-optic applications owing to their fast response times and quasi-polarization-independent phase modulation capabilities. Various approaches have recently been proposed to control the crystal orientation of BPs on substrates, but their basic orientation properties on standard, unidirectionally orienting substrates had not been investigated in detail. Here, detailed studies have been made on the Kossel diagrams of BPs on unidirectionally orienting substrates to understand the three-dimensional crystal orientation of BPs. We find that BPs show strong thermal hysteresis and that the structure of the preceding phase determines the orientation of BPs. Specifically, the BP II-I transition is accompanied by a rotation of the crystal such that the crystal direction defined by certain low-value Miller indices transform into different directions, and within the allowed rotations, different azimuthal configurations are obtained in the same cell depending on the thermal process. Our findings demonstrate that, for the alignment control of BPs, the thermal process is as important as the properties of the alignment layer.

DOI： 10.1117/12.2323159

Language：English   Publishing type：Research paper (other academic)  

Kossel diagrams visualize the directions of strong Bragg reflections from a specimen with periodic ordering. They have played a pivotal role in the determination of the symmetry of cholesteric blue phases, and in the investigation of their structural changes under an electric field. In this work, we present direct numerical calculations of the Kossel diagrams of cholesteric blue phases by solving the Maxwell equations for the transmission and reflection of light incident upon a finite-thickness blue phase cell. Calculated Kossel diagrams are in good agreement with what is expected as a result of Bragg reflections, although some differences are present.

DOI： 10.1117/12.2286290

Language：English   Publishing type：Research paper (scientific journal)  

A new series of chiral dopants, (R)-6,6′-halogenated (1b-1e, X = F, Cl, Br and I) and -methylated (1f) binaphthyl compounds, were designed and synthesized to create chiral liquid crystals by doping them into an achiral nematic liquid crystal (NLC). The influence of halogen (X = F, Cl, Br and I) and methyl substituent factors, such as steric, polar, and polarizability properties, on the helical twisting power (HTP) and their temperature dependences on the chiral dopants were investigated in two host NLCs with different characteristics, fluorinated JC-1041XX and N-(4-methoxybenzylidene)-4-butylaniline (MBBA). The chiral dopants possessing less steric and larger polarizability factors increased the HTP values. The structural similarity and electrostatic arene-arene interactions between the chiral dopants and the NLC molecules also exerted important influences on these values. The temperature dependence of the HTP (HTP_t.d.) values also correlated well with the steric and polarizability substituents factors in the two host NLCs. Their correlation coefficients (R²) depended on the molecular structural similarity between the chiral dopant and the NLC.

DOI： 10.1039/c7ra12465a

Language：English   Publishing type：Research paper (scientific journal)  

Invited for this month's cover picture is the groups of Professor Hirotsugu Kikuchi and Dr. Yasushi Okumura at the Institute for Materials Chemistry and Engineering at Kyushu University (Japan). External dynamic control of molecular self-organized superstructures with unique features has been researched, as these structures are applicable to chiral molecular devices. The cover picture shows photocontrol of selective reflection color that originated from the self-organized helical structure of chiral nematic liquid crystals (N*LCs) using closed-/open-type dopants. The drastic structure changes of the dopants by light stimuli enable reversible broad-spectrum control of selective reflections of N*LCs with opposite helical sign. Read the full text of the Full Paper at 10.1002/open.201700121.

DOI： 10.1002/open.201700170

Language：English   Publishing type：Research paper (scientific journal)  

We demonstrate reversible RGB-color photocontrol of a chiral nematic liquid crystal (N*LC) by using newly synthesized closed- and open-type chiral dopants. The photoswitching elements in the dopants are azobenzene units on axially chiral binaphthyl cores. Owing to cis–trans photoisomerization of the azobenzene units, both closed- and open-type compounds showed higher solubility, larger helical twisting power (HTP), and larger changes in HTP than conventional chiral dopants in host LCs. Thus, even at very low dopant concentrations, we successfully controlled the chirality of the induced helical structure of the N*LCs. Consequently, the N*LCs reflected right- and left-handed circularly polarized light (CPL) under a light stimulus. In the N*LCs with closed-type chiral dopants, the RGB-color reflection was reversibly controlled within several seconds. Interestingly, the open-type chiral dopant reversibly inverted CPL with opposite handedness in the near and short-wave IR regions. These novel materials are expected to realize new applications and perspectives in color information and similar technologies.

DOI： 10.1002/open.201700121

Language：English   Publishing type：Research paper (scientific journal)  

An anomalously large dielectric permittivity of ≈10⁴ is found in the mesophase temperature range (MP phase) wherein high fluidity is observed for a liquid-crystal compound having a 1,3-dioxane unit in the mesogenic core (DIO). In this temperature range, no sharp X-ray diffraction peak is observed at both small and wide Bragg angles, similar to that for a nematic phase; however, an inhomogeneous sandy texture or broken Schlieren one is observed via polarizing optical microscopy, unlike that for a conventional nematic phase. DIO exhibits polarization switching with a large polarization value, i.e., P = 4.4 µC cm⁻², and a parallelogram-shaped polarization–electric field hysteresis loop in the MP phase. The inhomogeneously aligned DIO in the absence of an electric field adopts a uniform orientation along an applied electric field when field-induced polarization switching occurs. Furthermore, sufficiently larger second-harmonic generation is observed for DIO in the MP phase. Second-harmonic-generation interferometry clearly shows that the sense of polarization is inverted when the +/− sign of the applied electric field in MP is reversed. These results suggest that a unidirectional, ferroelectric-like parallel polar arrangement of the molecules is generated along the director in the MP phase.

DOI： 10.1002/adma.201702354

Language：English   Publishing type：Research paper (scientific journal)  

Nowadays as the development of cell phone and satellite communications, liquid crystal materials have attracted considerable attention for realizing these electrically controllable microwave and milliwave components. As usual, nematic liquid crystal is mainly used for microstrip line (MSL) phase shifter, but when driving voltage is removed the response time is very long. In this study, we discuss about using polymer stabilized nematic liquid crystals with UV polymerization for improving the response time in MSL phase shifter in which phase shift is about two times larger than that in CPW phase shifter.

DOI： https://doi.org/10.1002/ecj.12033

Language：English   Publishing type：Research paper (scientific journal)  

Weak anchoring of liquid crystals (LCs) can, in principle, have the potential to provide lower operating voltage systems with an improved electro-optic response. The creation of such a liquid crystal system is an important goal for next-generation displays, including polymer-stabilized blue phases. Herein, we report a new method of weak anchoring for LCs in contact with uniquely designed amorphous side-chain copolymers that feature both mesogenic and non-mesogenic units. The mesogenic pendant enhances the compatibility with the LC molecules, while the non-mesogenic part reduces the possible azimuthal anchoring energy of the mesogenic side-chain on LCs. The copolymers with mesogenic pendants bearing polar and non-polar end groups favor planar and homeotropic alignments, respectively. Interestingly, LCs in a glass plate cell coated with these side-chain non-liquid crystalline copolymers showed anchoring transitions and weak anchoring interface formation at precise temperatures. The weak anchoring nature of LCs on copolymer surfaces was confirmed by their easy response to an applied magnetic field. These results suggest that the copolymers perform an important function as weak anchoring surfaces for nematic LCs.

DOI： 10.1016/j.polymer.2016.12.012

Language：English   Publishing type：Research paper (scientific journal)  

The miscibility of chiral molecules to unimodal side-chain nematic liquid crystalline (LC) polymers was studied to generate chiral nematic phases. Chiral dopants, a phenyl benzoate derivative S-811 and an isosorbide dibenzoate derivative ISO-(6OBA)₂ were miscible to the nematic LC polymer PMA(4OPB) tethering phenyl benzoate moieties as side-chain mesogens by preparing mixtures in solutions rather than directly melting the powders together. Nematic LC random copolymers containing non-LC side chains were designed to promote the interaction between mesogens and chiral molecules. The introduction of hexyl chains as side chains randomly into nematic LC polymers improved the miscibility of chiral molecules of an isosorbide dibenzoate derivative with hexyl tails. The hexyl chains of the polymer provided spaces for the chiral molecules and caused alkyl–alkyl interactions. We demonstrated that the randomly introduced hexyl chains promoted the interaction of chiral molecules with LC mesogens to generate chiral nematic phases.

DOI： 10.1246/bcsj.20160343

Language：English   Publishing type：Research paper (other academic)  

An anomalously large dielectric permittivity of about ten thousand is found for an LC compound having a 1,3-dioxane unit in the mesogen core part (DIO). Our experimental results suggest that a ferroelectric-like unidirectional parallel polar arrangement of the molecules is generated along the director in an LC phase of DIO.

Language：English   Publishing type：Research paper (scientific journal)  

2,5-Bis(diarylethenyl)thiophenes (1) and their bithiophene (2) and terthiophene (3) homologues were designed as a new series of violene/cyanine-hybrid-type electrochromic materials. Alkoxyphenyl and dialkylaminophenyl groups are used as the aryl group in the cyanine parts of 1/2/3O and 1/2/3N, respectively, which emit fluorescence in the neutral state but not in the oxidized state. Voltammetric analyses of 18 newly prepared electron donors show that they all undergo two reversible one-electron oxidations. Redox potentials, UV-vis spectral features, and fluorescence quantum yields are important parameters for characterizing the present electrochromic behavior with a fluorescence response, and can be finely tuned by changing aryl groups in the cyanine part, the number of thiophene rings in the violene part, and the alkyl-chain length of the alkoxyphenyl or diaklylaminophenyl groups (R = CH₃, C₈H₁₇, C₁₆H₃₃), which makes this a versatile platform for the design of novel electrochromic materials.

DOI： 10.1139/cjc-2016-0222

Language：English   Publishing type：Research paper (scientific journal)  

Polymer-stabilized blue phase liquid crystal (PS-BPLC) is emerging as a strong competitor for next-generation liquid crystal displays and optoelectronic devices. However, the realization of technologies built on PS-BPLC requires lowering of driving voltage without sacrificing other desirable properties of blue phase liquid crystals. Here, we present a new method for voltage reduction in PS-BPLC based on the stabilization of BPLC with weak anchoring interface inducing acrylate monomers. This method provides significant voltage reduction while maintaining the electro-optical performance of BPLCs at the same time. We believe that this approach has a great potential in developing high-performance photonic devices and displays based on liquid crystals.

DOI： 10.1002/slct.201701233

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DOI： 10.1039/C6CP03614G

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DOI： 10.1117/12.2209210

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DOI： 10.1080/02678292.2015.1055602

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DOI： 10.1039/c5sm00711a

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DOI： 10.1103/PhysRevE.91.022503

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DOI： 10.1080/15421406.2014.956398

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DOI： 10.3390/cryst5010163

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DOI： 10.1002/marc.201400333

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DOI： 10.1039/c4tc01049c

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DOI： 10.1080/02678292.2014.936531

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DOI： 10.1002/cphc.201301142

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DOI： 10.1246/cl.131169

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DOI： 10.1038/pj.2013.98

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DOI： 10.1246/cl.140163

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DOI： 10.1364/OME.4.000960

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DOI： 10.1103/PhysRevE.89.012506

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DOI： 10.7567/JJAP.53.01AE08

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DOI： 10.1364/OME.3.002086

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DOI： 10.1002/cphc.201300093

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Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (bulletin of university, research institution)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English  

Language：Japanese  

Vol. 9(2), 82-95(2005).

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1002/adma.200400639

Language：English  

Language：English  

Responsible for pages：Vol. 128, 99-117   Language：English   Book type：Scholarly book

Responsible for pages：pp.169-173, pp.420-424   Language：Japanese   Book type：Scholarly book

Event date： 2023.9

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：高松市   Country：Japan  

Event date： 2023.9

Language：Japanese  

Venue：東京   Country：Japan  

Event date： 2023.9

Language：Japanese  

Venue：東京   Country：Japan  

Event date： 2023.9

Language：Japanese  

Venue：東京   Country：Japan  

Event date： 2023.9

Language：Japanese  

Venue：東京   Country：Japan  

Event date： 2023.9

Language：Japanese  

Venue：東京   Country：Japan  

Event date： 2023.9

Language：English   Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Event date： 2023.9

Language：English   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2022.9

Language：English   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2022.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2022.9

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2022.9

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2022.9

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2022.9

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2022.9

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2022.9

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2022.7

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2022.7

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2022.6

Language：English   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2021.9

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2021.9

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2021.9

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2021.9

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2021.9

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2020.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2020.9

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2020.9

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Event date： 2020.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2020.9

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2020.9

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2020.5

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Event date： 2016.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京大学   Country：Japan  

Event date： 2010.7 - 2011.7

Presentation type：Oral presentation (invited, special)  

Venue：Krakow, Poland   Country：Poland  

Event date： 2010.7

Presentation type：Oral presentation (general)  

Venue：Cetraro, Italy   Country：Italy  

Event date： 2010.1

Presentation type：Oral presentation (general)  

Venue：San Francisco   Country：United States  

Event date： 2009.12

Presentation type：Oral presentation (general)  

Venue：新竹   Country：Taiwan, Province of China  

Event date： 2009.12

Presentation type：Oral presentation (general)  

Venue：Miyazaki   Country：Japan  

Event date： 2009.11

Presentation type：Oral presentation (general)  

Venue：Tokyo   Country：Japan  

Event date： 2009.10

Presentation type：Oral presentation (general)  

Venue：広州   Country：China  

Event date： 2009.9

Presentation type：Oral presentation (general)  

Venue：Erice   Country：Italy  

Event date： 2009.7

Presentation type：Oral presentation (general)  

Venue：Nara   Country：Japan  

Event date： 2009.6

Presentation type：Oral presentation (general)  

Venue：San Antonio   Country：United States  

Event date： 2009.5 - 2009.3

Presentation type：Oral presentation (general)  

Venue：Tokyo   Country：Japan  

Event date： 2009.3

Presentation type：Oral presentation (general)  

Venue：Miyazaki   Country：Japan  

Event date： 2009.3

Presentation type：Oral presentation (general)  

Venue：千葉   Country：Japan  

Event date： 2009.1

Presentation type：Oral presentation (general)  

Venue：Jeju, Korea   Country：Korea, Republic of  

Event date： 2008.12

Presentation type：Oral presentation (general)  

Country：Korea, Republic of  

Event date： 2008.12

Country：Japan  

Event date： 2008.12

Country：Japan  

Event date： 2008.12

Country：Japan  

Event date： 2008.12

Country：Japan  

Event date： 2008.12

Country：Japan  

Event date： 2008.12

Country：Japan  

Event date： 2008.12

Country：Japan  

Event date： 2008.12

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2008.12

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2008.9

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2008.8

Presentation type：Oral presentation (general)  

Venue：Yeungnam University   Country：Korea, Republic of  

Event date： 2008.8

Presentation type：Oral presentation (general)  

Venue：Long Beach, California   Country：United States  

Event date： 2008.8

Country：Japan  

Event date： 2008.8

Country：Japan  

Event date： 2008.8

Country：Japan  

Event date： 2008.8

Presentation type：Oral presentation (general)  

Venue：Lisbon   Country：Portugal  

Event date： 2008.8

Presentation type：Oral presentation (general)  

Venue：福岡   Country：Japan  

Event date： 2008.8

Country：Japan  

Event date： 2008.8

Venue：東京   Country：Japan  

Event date： 2008.8

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2008.8

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2008.8

Presentation type：Oral presentation (general)  

Venue：仙台   Country：Japan  

Event date： 2008.8

Presentation type：Oral presentation (general)  

Venue：千葉   Country：Japan  

Event date： 2008.8

Presentation type：Oral presentation (general)  

Country：United States  

Event date： 2008.6

Presentation type：Oral presentation (general)  

Country：Korea, Republic of  

Event date： 2008.6

Country：Korea, Republic of  

Event date： 2008.6

Country：Korea, Republic of  

Event date： 2008.6

Country：Korea, Republic of  

Event date： 2008.6

Country：Korea, Republic of  

Event date： 2008.6

Presentation type：Oral presentation (general)  

Country：Korea, Republic of  

Event date： 2008.6

Presentation type：Oral presentation (general)  

Country：Korea, Republic of  

Event date： 2008.6

Presentation type：Oral presentation (general)  

Country：Korea, Republic of  

Event date： 2008.5

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2008.5

Presentation type：Oral presentation (general)  

Country：Korea, Republic of  

Event date： 2008.4

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2008.3

Presentation type：Oral presentation (general)  

Venue：名古屋   Country：Japan  

Event date： 2008.3

Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2008.3

Country：Japan  

Event date： 2008.3

Country：Japan  

Presentation type：Symposium, workshop panel (public)  

Venue：東京   Country：Japan  

Presentation type：Oral presentation (general)  

Country：Slovenia  

Presentation type：Oral presentation (general)  

Venue：兵庫   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：福岡   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：北京   Country：China  

Country：Japan  

Country：Japan  

Country：Japan  

Country：Japan  

Presentation type：Oral presentation (general)  

Country：Italy  

Country：Japan  

Country：Japan  

Country：Japan  

Country：Japan  

Country：Japan  

Country：Japan  

Country：Japan  

Country：Japan  

Country：Japan  

Country：Japan  

Country：Japan  

Country：Japan  

Language：English   Presentation type：Oral presentation (general)  

Venue：Los Angeles   Country：United States  

Language：English   Presentation type：Oral presentation (general)  

Venue：Mainz   Country：Germany  

Language：English   Presentation type：Oral presentation (general)  

Venue：Daejeon   Country：Korea, Republic of  

Language：English   Presentation type：Oral presentation (general)  

Venue：Darmstadt   Country：Germany  

Language：English   Presentation type：Oral presentation (general)  

Venue：Honolulu   Country：United States  

Language：English   Presentation type：Oral presentation (general)  

Venue：Saga   Country：Japan  

Language：English   Presentation type：Oral presentation (general)  

Venue：Ibaraki   Country：Japan  

Language：English   Presentation type：Oral presentation (general)  

Venue：Ravenna   Country：Italy  

Language：English   Presentation type：Oral presentation (general)  

Venue：San Francisco   Country：United States  

Language：English   Presentation type：Oral presentation (general)  

Venue：Tokyo   Country：Japan  

Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

Type：Peer review 

Number of peer-reviewed articles in foreign language journals：2

Type：Competition, symposium, etc. 

Number of participants：754

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Scientific advice/Review 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc.