Synthesis, structure and properties of coagulated ultrathin membranes

The Coulomb interactions between charged surfactants and multivalent counter-ions can be used to form coagulated cross-linked membranes at the surface of water. We have systematically measured the kinetics of the two-dimensional gelation and the rheological properties of the stabilized films. The membranes, thus prepared, exhibit striking rubber-elastic features. The results of Brewster-Angle-Microscopy indicate that these films consist of disc-like aggregates, having typical diameters of about 10 mu m. These particles are in close contact and form fractal network clusters. The shape of these structures is in general agreement with aggregates calculated from percolation theories.