The spreading of insoluble surfactant at the free surface of a deep fluid layer

The unsteady spreading of an insoluble monolayer containing a fixed mass of surface-active material over the initially horizontal free surface of a viscous fluid layer is investigated. A how driving the spreading is induced by gradients in surface tension, which arise from the nonuniform surfactant distribution. Distinct phases in the flow's dynamics are distinguished by a time T = H-0(2)/v, where H-0 is the fluid depth and v its viscosity. For times t