Kenji Kishimoto

Columnar liquid crystalline π-conjugated oligothiophenes

Polycatenar oligothiophenes possessing three alkoxy chains at each terminal self-organise into columnar liquid crystalline phases, and one-dimensional columnar stacks can be oriented uniaxially by mechanical shearing in the mesophases.

Electrooptical properties of liquid-crystalline physical gels: a new oligo(amino acid) gelator for light scattering display materialsElectronic supplementary information (ESI) available: AFM and SEM images of the aggregates of gelators 1???3. See http://www.rsc.org/suppdata/jm/b2/b201484j/

Nematic liquid-crystalline (LC) physical gels suitable for light scattering electrooptical displays have been prepared from a nematic liquid crystal and a low molecular weight gelator containing an oligo(L-isoleucine) moiety. The number of amino acid moieties of the gelators has a great effect on the gelation ability and electrooptical behaviour of the LC gels. A gelator having three L-isoleucine moieties forms LC gels most efficiently. The use of the gelator leads to microphase separation where fibres with a diameter of ca. 30 nm finely disperse in liquid crystals. Such structures are suitable for the induction of high light scattering. The light scattering states are electrically switched to transparent states in liquid crystal cells. The contrast of light transmittance and driving voltages are improved by the tuning of the gelator concentrations. A gelator having two L-isoleucine moieties exhibits poor gelation ability. A mono-amino acid gelator forms LC gels showing lower light scattering, although they are applicable to twisted nematic mode.

Light Scattering Electrooptic Behavior of Liquid-Crystalline Physical Gels — Effects of Microphase-Separated Morphologies

Light scattering electrooptic behavior has been examined for liquid-crystalline physical gels consisting of a room temperature nematic liquid crystal and amino acid gelators. Electrooptic properties of the gels depend on the morphologies of the hydrogen-bonded aggregates. We show that liquid-crystalline gels comprising of randomly dispersed networks have potentials for light scattering electrooptic materials.

Self‐assembly of liquid crystalline triphenylene–oligo(ethylene oxide)–triphenylene molecules and their complexes with lithium triflate

Mesomorphic dimeric molecules consisting of discotic triphenylene rigid units and flexible ethylene oxide spacers have been prepared. The liquid crystalline behaviour is greatly dependent on the length of the ethylene oxide chains. The miscibility and phase behaviour have been examined for mixtures of the materials with lithium triflate.

Two Dimensionally Ion-Conductive Liquid Crystals of Cholesterol/Tetra(Ethylene Oxide) Block Molecules

ABSTRACT Two-dimensionally ion-conductive liquid crystals have been simply obtained by self-assembly of a cholesterol/tetra(ethylene oxide) block molecule and lithium triflate. Nanophase-segregation between cholesterol and tetra(ethylene oxide) blocks leads to the formation of a smectic A liquid crystalline phase in a wide range of temperature. A homeotropically aligned lithium salt complex in the smectic A phase shows two-dimensional ionic conductivity. The ionic conductivities parallel to the smectic layers are higher than those perpendicular to the layers. The maximum value of the anisotropy in the ionic conductivity is about 2.4 × 103 at 30°C.