Phase transitions and separations at interfaces

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Technological advances rely increasingly on materials which do not exist in nature. Yet, we look at nature and its inventions for inspiration and ideas for materials research solutions. What nature teaches us in materials science is that the most sophisticated solutions are materials that are complex, that self-assemble, that exist only outside the thermodynamic equilibrium, that have different properties in bulk and at their surfaces. To take the same approach in the laboratory requires an interdisciplinary approach. We need Surface Chemistry and Surface Physics to tailor the properties at the surface, we need Materials Science and Engineering to manufacture and modify the substrates, and we need Non-equilibrium thermodynamics and Chemical kinetics to define an operational material with reduced dimensions or layered structures. Advances in this field do not come easy as increasingly complex systems display a wide range of competing processes; a designed improvement is accompanied by competing efefcts that are adverse for other important materials properties. The current project aims at tackling one particular type of challenge in materials manufacturing: phase separation and phase transition processes in heterogeneous systems. We all know that water and oil don't mix; if you force them together they start to separate. The final equilibrium of separated systems is not interesting; however, if we can freeze an intermediate, partially separated state, then we may have obtained a system with novel properties and, hopefully, novel applications. Phase separations occur in many processes, ranging from thin film or heterostructure growth of semiconductor systems to the formation of artifical or natural biomembranes. Our research aims at understanding the many aspects of these dynamic processes and explore possibilities to interfere or even steer them in a predictable fashion.