Thin films are being increasingly used in advanced technological applications. The use of these films as coatings is often limited by their lack of stability due to wettability properties of the substrates; however, one can employ the instabilities to create complex microscopic functional structures. Furthermore, the development of microfluidic applications such as DNA microarrays or drug screening techniques requires a fundamental understanding of static and dynamic interfacial phenomena. Fluids of interest in biology, chemistry, and in various applications are rarely simple single-phase fluids.

These systems pose fundamental questions that become more challenging when free interfaces and wetting properties of the substrate are involved. For instance, for a thin film of a polymeric blend the dynamics of the decomposition within the film and the dewetting of the film itself couple. This allows for new pathways of structuring like decomposition induced dewetting. Normally, the dynamics of a binary mixture is described by the so called model-H coupling momentum transport (Navier-Stokes) and nonlinear diffusion (Cahn-Hilliard). We have extended in previous works the model-H by incorporating boundary conditions that allow to describe an evolving free surface. The present project will focus on the study of relevant problems arising in films of binary mixtures such as polymer blends and flows of binary mixtures.

Based on extensions of model-H the following objectives will be pursued:

• to study the effect of external electric fields on the structure formation, dynamics, phase coexistence, and stability of films of binary mixtures,
• to understand the effect of surface tension and finite surface deflections on the phase separation and dynamics of binary mixtures,
• to study the interplay between varying dewetting properties and evolution of binary mixtures.