Tom Witelski, Duke University


Coarsening dynamics of thin fluid films


Abstract: The study of instabilities of thin fluid films on solid surfaces is of great importance in many industrial processes. Such instabilities lead to rupture, the formation of dry spots, and further morphological changes that promote non-uniformity of coatings; these behaviors in unstable thin films are generally called dewetting. To account for these effects, lubrication models of fluid flow must incorporate terms describing the influence of material properties of the solid and fluid. The resulting nonlinear PDE can accurately reproduce the complex physical pattern formation observed in experiments. Following initial transients, the film breaks up into an array of droplets. The evolution of this system can be represented in terms of coupled ODEs for the masses and positions of the droplets. Regimes where droplet coarsening by each of two mechanisms (collision and collapse) are identified, and power laws for the statistics of the coarsening processes are explained.

Address: Mathematics Department, Duke University, Box 90320 Durham, NC 27708-0320. Go to Professor Witelski's website.