A family of liquid crystalline polyarylenevinylenes

Akagi, Kazuo; Oguma, Jun; Shibata, Shotaro; Toyoshima, R.; Osaka, Itaru; Shirakawa, Hideki

doi:10.1016/s0379-6779(98)00754-1

Cited by 25 publications

(10 citation statements)

References 5 publications

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“…11). 41 Besides, polymers show relatively high conductivity of 10 À3 S/cm under nonoriented condition, which is higher by 3-4 order of magnitude than those of aligned polyacetylene derivatives containing similar mesogens. The results suggest an enhanced coplanarity in the PPV main chains.…”

Section: Side-chain Lc Conjugated Polymersmentioning

confidence: 97%

“…38 In addition to PAs, many other conjugated polymers incorporating with LC side groups have also been synthesized and characterized. Akagi and coworkers 39 synthesized a number of LC polyarylenes and polyarylenevinylenes, including poly(p-phenylene), PPV, [39][40][41] and polythienylenevinylene. 41,42 Chart 10 shows the chemical structures of some side-chain LC conjugated polymers.…”

Section: Side-chain Lc Conjugated Polymersmentioning

confidence: 99%

“…Akagi and coworkers 39 synthesized a number of LC polyarylenes and polyarylenevinylenes, including poly(p-phenylene), PPV, [39][40][41] and polythienylenevinylene. 41,42 Chart 10 shows the chemical structures of some side-chain LC conjugated polymers. Cyanobiphenyl (CB) or phenylcyclohexyl (PCH) mesogenic cores were linked to p-conjugated main chain through alkyl spacer.…”

Section: Side-chain Lc Conjugated Polymersmentioning

confidence: 99%

“…In some cases, it shows stronger emission in perpendicular to rubbing direction, especially for those side-chain LC conjugated polymers. 41,43 Taking the examples of polymer P12, the light emitted from the rubbed film was preferentially polarized perpendicular to the rubbing direction, as shown in Figure 18. This is because rubbing at thermotropic LC phase induces the alignment of mesogenic side groups along the rubbing direction and the alignment of polymer backbones perpendicular to the rubbing direction.…”

Section: Polarized Emissionmentioning

confidence: 99%

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Liquid crystalline conjugated polymers and their applications in organic electronics

Yang

Hsu

2009

J. Polym. Sci. A Polym. Chem.

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This article describes the syntheses and electrooptical applications of liquid crystalline (LC) conjugated polymers, for example, poly(p-phenylene vinylene), polyfluorene, polythiophene, and other conjugated polymers. The polymerization involves several mechanisms: the Gilch route, Heck coupling, or Knoevenagel condensation for poly(pphenylenevinylene)s, the Suzukior Yamamoto-coupling reaction for polyfluorenes, and miscellaneous coupling reactions for other conjugated polymers. These LC conjugated polymers are classified into two types: conjugated main chain polymers with long alkyl side chains, namely main-chain type LC polymers, and conjugated polymers grafting with mesogenic side groups, namely side-chain type LC conjugated polymers. In general, the former shows higher transition temperature and only nematic phase; the latter possesses lower transition temperature and more mesophases, for example, smectic and nematic phases, depending on the structure of mesogenic side chains. The fully conjugated main chain promises them as good candidates for polarized electroluminescent or fieldeffect devices. The polarized emission can be obtained by surface rubbing or thermal annealing in liquid crystalline phase, with maximum dichroic ratio more than 20. In addition, conjugated oligomers with LC properties are also included and discussed in this article. Several oligo-fluorene derivatives show outstanding polarized emission properties and potential use in LCD backlight application.

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Section: Side-chain Lc Conjugated Polymersmentioning

confidence: 97%

Section: Side-chain Lc Conjugated Polymersmentioning

confidence: 99%

Section: Side-chain Lc Conjugated Polymersmentioning

confidence: 99%

Section: Polarized Emissionmentioning

confidence: 99%

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Liquid crystalline conjugated polymers and their applications in organic electronics

Yang

Hsu

2009

J. Polym. Sci. A Polym. Chem.

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“…Main chain or side chain type liquid crystalline (LC) conjugated polymers are attracting current interests. This is because they are easily macroscopically aligned by external perturbation in LC phase, giving anisotropic optical and electrical properties, such as linearly polarized absorption and fluorescence and anisotropic transport phenomena [1][2][3][4][5]. Besides, chiral or helical conjugated polymers are of recent interest since they afford circularly polarized fluorescence (CPF) as well as circularly dichroic absorption [6,7].…”

mentioning

confidence: 99%

Control of Linearly and Circularly Polarized Fluorescences on Photoresponsive Liquid Crystalline and Chiral Conjugated Polymer

Hayasaka¹,

Tamura²,

Akagi³

2007

Trans. Mat. Res. Soc. Japan

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A photoresponsive chiral substituent consisting of dithienylethene moiety and chiral center was introduced into the side chain of bithienylene-phenylene copolymer. Reversible photoisomerization of the dithienylethene moiety was observed in both in CHCh solution and in cast film. Fluorescence of the polymer was quenched when the photochromic moiety changed from an open form to a closed one upon an irradiation of ultraviolet light. The quenched fluorescence was recovered through the reverse photoisomerization using visible light. Polarizing optical microscope demonstrated that the polymer has a main chain type liquid crystallinity. The polymer aligned by a rubbing technique exhibited a linearly polarized fluorescence (LPF). The cast film of the polymer showed Cotton effects in the region of 1t -n* transition of main chain in both circularly dichroism (CD) and circularly polarized fluorescence (CPF) spectra. The anisotropic fluorescence was controlled by the photochemical switching.

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Liquid Crystalline and Electroresponsive Polythiophenes

Akagi

2009

Handbook of Thiophene‐Based Materials

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A family of liquid crystalline polyarylenevinylenes

Cited by 25 publications

References 5 publications

Liquid crystalline conjugated polymers and their applications in organic electronics

Liquid crystalline conjugated polymers and their applications in organic electronics

Control of Linearly and Circularly Polarized Fluorescences on Photoresponsive Liquid Crystalline and Chiral Conjugated Polymer

Liquid Crystalline and Electroresponsive Polythiophenes

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