INNER STRUCTURE OF CONDENSED-PHASE DOMAINS IN MONOLAYERS AT THE AIR-WATER-INTERFACE

The inner structure of condensed phase domains in monolayers at the ai r-water interface is studied by Brewster angle microscopy. Condensed p hase domains of l-monoglycerides exhibit a 7-fold substructure. Seven segments of different molecular orientation meet at a center. The atte ntion is focused on the orientational relations of the partial lattice s separated by a sharp boundary for explaining the observed segment nu mber. The boundary lines of the segments are considered to be along de nse lattice rows. Thus a defined change of the molecular orientation o ccurs at a segment boundary. The interdependence of the lattice parame ters and the number of segments is described based on a centered ortho rhombic lattice. The geometrical analysis of the inner domain structur e shows that the chains are tilted along the bisector of each segment and that the segment boundaries are along next nearest neighbor direct ions.