COMPARISON OF ENANTIOMERIC AND RACEMIC MONOLAYERS OF N-STEAROYLSERINEMETHYL-ESTER BY FLUORESCENCE MICROSCOPY

Monolayers of L-, D-, and racemic N-stearoylserine methyl ester (SSME) were examined using fluorescence microscopy and surface pressure isot herm measurements. Fluorescence microscopy reveals distinct difference s in the condensed phase domain structures between the enantiomeric an d racemic monolayers. The racemic SSME monolayer exhibits isotropic gr owth of the condensed phase, but with the formation of counterclockwis e and clockwise hooks at the periphery of the domains. In contrast, th e condensed phase of the L-SSME or D-SSME monolayers exhibits dendriti c growth. The formation of condensed phase domains with the macroscopi c curvature dependent upon the headgroup chirality is also observed. I n the racemic monolayer, domains with both clockwise and counterclockw ise curvature are observed; however, the L-SSME monolayer shows only d omains with counterclockwise curvature and the D-SSME monolayer shows only domains with clockwise curvature. Fluorescence anisotropy is obse rvable within the condensed phase at lower temperature, suggesting the presence of long-range tilt order.