TILT STRIPE TEXTURES IN LANGMUIR MONOLAYERS OF FATTY-ACIDS

Quantitative studies are described of striped textures in Langmuir monolayers of tetradecanoic and pentadecanoic acids. The textures, which are the result of modulations of the tilt azimuths of the molecules, have been visualized with polarized fluorescence microscopy. The stripe widths change with pressure and temperature. When the monolayer is compressed beyond a threshold pressure, the stripes become unstable and form a zig-zag pattern, which is likely the result of a crossover between the bend and splay elastic constants in the monolayer.