Fluorescence Microscopy Observations of Domain Structures in Langmuir Monolayers of N-stearoylserine Methyl Ester and N-stearoylvaline at Intermediate Enantiomeric Compositions

Langmuir monolayers of N-stearoylvaline and N-stearoylserine methyl ester were studied at compositions intermediate between the racemic and the purely enantiomeric using surface pressure isotherm measurements and fluorescence microscopy observations. The transition pressure was found to vary smoothly with composition for both compounds. Curved dendritic forms were observed at intermediate compositions, indicating an anisotropy in the line tension. A novel crossover from dendritic to curved domain morphology at slower domain growth rate is reported for the films of enantiomeric N-stearoylserine methyl ester.