Novel liquid crystalline structure in langmuir monolayers of amphiphilic azobenzene derivative

Yuka Tabe, Hiroshi Yokoyama

Research output: Contribution to journalArticle

28 Citations (Scopus)

Abstract

Depolarized Brewster-angle microscopy revealed a novel two-dimensional (2D) mesophase in Langmuir monolayers of 4-octyl-4′-(3-carboxytrimethyleneoxy) azobenzene, characterized by ubiquitous schlieren textures resulting from the long-range order of in-plane molecular orientations. The lack of half-integral strength disclinations and the presence of a regular array of π-walls, across which the in-plane orientation changes by 180 degrees, indicate the vectorial nature of the underlying order parameter. The monolayer can, therefore, be viewed as a single layer of a bulk smectic C phase or as a 2D polar nematic phase, except for the obvious absence of mirror symmetry with respect to the layer plane. In contrast to the experience with bulk liquid crystalline phases, higher-order point disclinations were often found stable in the monolayer.

Original languageEnglish
Pages (from-to)2472-2476
Number of pages5
JournalJournal of the Physical Society of Japan
Volume63
Issue number7
Publication statusPublished - 1994 Jul
Externally publishedYes

    Fingerprint

Keywords

  • π-wall
  • 2D liquid crystal
  • Brewster-angle microscopy
  • Langmuir monolayer
  • Modulated phase
  • Point disclination
  • Schlieren texture

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this