Monomolecular films of surfactants at the air-water interface are easy to prepare and to handle, and enable a broad variety of techniques to be used. As in other model-systems mimicking membranes, two-phases are observed in several experimental conditions. This Chapter compares the results found using this model membrane with other models and describes some of the techniques applicable to lipid monolayers. The factors underlying their texture when two phases coexist are summarized, with special attention to line tension, an important parameter in both nucleation and growth, as well as the final domain shape. Finally, the effects of the presence of two-phases on the observed mechanical properties of the film (elastic compressibility and shear viscosity) are detailed.Fil: Wilke, Natalia. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Biológica; Argentina.Fil: Wilke, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones en Química Biológica de Córdoba, Argentina.Biofísic
