Theoretical description of phase behavior in micro-evaporators

• Applicant: Dr. Michael Schindler
• Subject Area: Theoretical Condensed Matter Physics
• Term: from 2007 to 2009
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 57096061

Mixtures of a fluid with additives can display rich phase behavior, which one would like to characterize in many systems. Examples include suspensions of colloids, surfactants in fluids, and solutes such as salts in solvents. They are encountered in diverse industries as well as in experimental science. Depending on the size and the complexity of the additives, there can be numerous resulting phases. If the system is driven out of equilibrium, the number of states or phases even increases with many metastable states, possibly depending on the driving and on the history of the sample. The nucleation and the growth of such phases gives insight into the kinetics of the phase changes. We want to investigate the phase behavior of various mixtures in recently proposed micro-evaporator devices, where a flow is induced by permeation of the solvent through thin bounding membranes. The novel device is similar to existing filtration devices, but the type of driving is different. We expect further insight into the kinetics of the phase changes, as it should depend strongly on the type of driving. The theoretical modeling of the phase behavior is planned to be done in direct interaction with the experimentalists who developed the device and are currently applying it to many different systems for both fundamental and industrial studies. The theoretical description will borrow from non-equilibrium thermodynamics, from hydrodynamic descriptions, from the theory of phase transitions as well as from nucleation theories.

• DFG Programme: Research Fellowships
• International Connection: France
• Host: Dr. Armand Ajdari