BOND-ORIENTATIONAL ORDER IN LANGMUIR-BLODGETT SURFACTANT MONOLAYERS

Cadmium stearate surfactant molecules assembled into monolayers by the Langmuir-Blodgett method exhibit bond-orientational order. Bond-orientational correlations extend over macroscopic distances on the order of a millimeter while translational correlations decay on a scale of tens of angstroms. The long axis of the molecules are tilted away from the surface normal but the tilt direction is disordered. Our results, obtained by transmission electron diffraction, suggest clustering of the hydrocarbon chains in the monolayer.