Surfactant-spreading and surface-compression disturbance on a thin viscous film

摘要: Spreading of new surfactant in the presence ofa pre-existing distribution is investigated both experimentally and theoretically for a thin viscous substrate. The experiments are designed to provide better understanding fundamental interfacial fluid dynamics spreading surfactants instilled into lung. Quantitative measurements rates were conducted using fluorescent that was excited by argon laser light as it spread on an air-glycerin interface petri dish. It found impedes spreading. However, microspheres used surface markers show facilitates propagation surface-compression disturbance, which travels faster than leading edge surfactant. experimental results compare well with theory developed lubrication approximations. An effective diffusivity film system be D eff = (E * Γ)/(μ/H), indicates disturbance propagates larger background concentration, Γ, constant slope σ -Γ relation, -E , smaller resistance, μ/H. Note Γ dimensional tension respectively, μ viscosity, H unperturbed thickness.