STARS, STRIPES AND SHELLS IN MONOLAYERS - SIMULATION OF THE MOLECULAR ARRANGEMENT IN SCHLIEREN STRUCTURES

Recent publications have reported on shell, star and stripe textures in monolayer films of long-chain fatty acids and esters at the air-water interface. observed with polarized fluorescence and Brewster angle microscopy (BAM). The difference in the brightness of the domains is related to a difference of the azimuthal tilt of the hydrocarbon chains of the molecules. We present model calculations concerning the various textures, observed by BAM using the 4 x 4 matrix algorithm of Berreman, J. Opt. Soc. Am., 6-2 (1972) 502-510. The calculations show that all observed textures are of splay type, with an azimuthal orientation directed to the inside of the shell or stripe in the case of a fatty acid and to the outside in the case of stars in methyl ester monolayers.