RESUMEN
Fluorescence recovery after photobleaching was used to characterize the diffusion of fluorescently labeled phospholipids at the oil/water interface for oil viscosities that varied over four orders of magnitude. Measurements were performed over a range of surface concentrations corresponding to molecular areas of 40-130 A(2)/molecule. As expected, the interfacial diffusion coefficient increased with molecular area, saturating at an area of approximately 100 A(2)/molecule. At molecular areas below approximately 80 A(2)/molecule, macroscopic domains of a condensed monolayer phase were observed; the diffusion of these domains was characterized by direct tracking and trajectory analysis. For oils with viscosity