Photonic manipulation of topological defects in liquid-crystal emulsions doped with azobenzene derivatives

Takahiro Yamamoto, Yuka Tabe, Hiroshi Yokoyama

    Research output: Contribution to journalArticle

    14 Citations (Scopus)

    Abstract

    By modulating liquid-crystal alignment on a colloidal sphere, we successfully manipulated topological defects in glycerol-droplet/liquid-crystal emulsions doped with amphiphilic azobenzene derivatives. At an initial state, a disclination loop (Saturn ring) could be observed around the droplet, in which the azobenzene molecules should adsorb onto the droplet and liquid crystal molecules align normally to the surface of the droplet. On irradiation with ultra-violet light (λ = 365 nm), the disclination loop was unfastened and transformed into two point defects called boojums. This should be attributed to the alignment change of the liquid crystal molecules from normal to planar arrangement triggered by trans-to-cis photoisomerization of the adsorbed azo-dyes. On irradiation with visible light causing cis-to-trans photoisomerization (λ = 435 nm), the boojums went back to the Saturn ring reversibly.

    Original languageEnglish
    Pages (from-to)81-84
    Number of pages4
    JournalThin Solid Films
    Volume509
    Issue number1-2
    DOIs
    Publication statusPublished - 2006 Jun 19

    Fingerprint

    Liquid Crystals
    Azobenzene
    Emulsions
    Liquid crystals
    Photonics
    emulsions
    manipulators
    liquid crystals
    photonics
    Saturn rings
    Derivatives
    Photoisomerization
    Defects
    defects
    Molecules
    Azo Compounds
    alignment
    Irradiation
    molecules
    irradiation

    Keywords

    • Azobenzene
    • Liquid-crystal colloids
    • Nano-structured liquid crystals
    • Photoisomerization

    ASJC Scopus subject areas

    • Surfaces, Coatings and Films
    • Condensed Matter Physics
    • Surfaces and Interfaces

    Cite this

    Photonic manipulation of topological defects in liquid-crystal emulsions doped with azobenzene derivatives. / Yamamoto, Takahiro; Tabe, Yuka; Yokoyama, Hiroshi.

    In: Thin Solid Films, Vol. 509, No. 1-2, 19.06.2006, p. 81-84.

    Research output: Contribution to journalArticle

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