Reactive Autophobic Spreading of Drops

We use a lubrication theory approximation to formulate a model for the reactive spreading of drops that deposit an autophobic monolayer of surfactant on a surface. The model consists of a Poisson equation on a moving domain with boundary conditions that depend on the history of the domain motion. We develop a numerical algorithm for solving the model, using the immersed interface method and the level-set method. Numerical solutions for traveling drops are qualitatively similar to experimental observations of reactive autophobic spreading.