Electron microscopic visualization of numerous two-dimensional crystal-like domains in a monolayer on an aqueous subphase.

Abstract

Two-dimensional microcrystal-like domain formation in a monolayer of 2-octadecyl-7, 7, 8, 8-tetracyanoquinodimehane was electron microscopically visualized. The electron microscopic examinations suggested that the co-existence of microcrystals and relatively fluid condensed form (s) in the so-called solid state of monolayer on an aqueous subphase. When the monolayer deposition was conducted at a surface pressure higher than the so-called collapsing pressure and its electron micrograph was obtained, no significant collapsed pattern could be visualized on the electron microscopic scale. On the basis of our finding, we assume that the collapsing pressure tentatively called in this study might not be the so-called collapsing pressure. Further monolayer compression might permit the formation of a large two-dimensional crystal-like domain in monolayer on the aqueous subphase.