Orientational correlations in two-dimensional liquid crystals studied by molecular dynamics simulation

Go Watanabe, Jun Ichi Saito, Nobuyuki Kato, Yuka Tabe

    Research output: Contribution to journalArticle

    6 Citations (Scopus)

    Abstract

    Orientational correlations in Langmuir monolayers of nematic and smectic-C liquid crystal (LC) phases are investigated by molecular dynamics simulation. In both phases, the orientational correlation functions decay algebraically yet with the different exponents of 1.9 and 0.2 for the nematic and the smectic-C monolayers, respectively. The power law decay, i.e., the absence of long-range orientational order, means the both monolayers should be the ideal 2D system with a continuous symmetry, whereas the large difference in the exponents of power law gives rise to the crucial difference in their optical properties; the nematic monolayer is optically isotropic while the smectic-C monolayer exhibits an anisotropy on the length scale of visible light. Since the exponent is inversely proportional to the molecular exchange energy, the averaged molecular interaction in the nematic monolayer should be an order of magnitude smaller than that in the smectic-C monolayer, which is ascribed to the low molecular density and the weak molecular dipole due to the water molecule. The relation between the molecular interaction and the orientational correlation calculated for the 2D LC system offers much information not only about the 2D LCs but also on the bulk system.

    Original languageEnglish
    Article number054513
    JournalJournal of Chemical Physics
    Volume134
    Issue number5
    DOIs
    Publication statusPublished - 2011 Feb 7

    Fingerprint

    Liquid Crystals
    Molecular dynamics
    Monolayers
    liquid crystals
    exponents
    molecular interactions
    molecular dynamics
    Computer simulation
    monomolecular films
    simulation
    decay
    Molecular interactions
    energy transfer
    dipoles
    optical properties
    anisotropy
    symmetry
    water
    molecules
    Anisotropy

    ASJC Scopus subject areas

    • Physics and Astronomy(all)
    • Physical and Theoretical Chemistry

    Cite this

    Orientational correlations in two-dimensional liquid crystals studied by molecular dynamics simulation. / Watanabe, Go; Saito, Jun Ichi; Kato, Nobuyuki; Tabe, Yuka.

    In: Journal of Chemical Physics, Vol. 134, No. 5, 054513, 07.02.2011.

    Research output: Contribution to journalArticle

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