In this study, we designed and synthesized novel liquid-crystalline polymers based on donor-acceptor architecture containing oxadiazole and carbazole moieties in the same side chain. The polymers showed liquid-crystalline phase and exhibited intense blue emission in film. Furthermore, they possess the bipolar character.

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The anisotropy of liquid-crystalline polymers (LCPs) and their easy processability allow the direct preparation of well-oriented thin films, leading to organic light emitting diodes (OLEDs) releasing polarized light. We synthesized the side-chain copolymers composed of the mesogenic monomer, which contains an oxadiazole (OXD) moiety and a fluorophenyl group, and the nonmesogenic monomers including OXD and various amine moieties. The synthesized copolymers showed LC behavior and emitted blue light. The polymer LEDs using the LC copolymers were fabricated by spin coating. The device showed polarized emission by introducing a mechanically rubbed PEDOT-PSS film as an alignment layer.

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We have fabricated checker patterns with photoalignment method to realize surface aligned nematic bistability. We took the advantage of the rewritability of an azo dye film for the patterning with single lithography process. The checker pattern with domain size of 1 micron and area of 40x40 mm² was fabricated. The surface bistable cell showed switching between the two states in orthogonal in-plane electric fields.

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Liquid crystalline materials having a coumarin skeleton at the terminal position were synthesized and their thermal properties were examined. Benzoate and biphenyl carboxylate derivatives show smectic phase in addition to nematic phase. Naphthyl derivatives, pn the other hand, show only a nematic phase.

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