The overarching goal of all our activities is to model complex fluid behavior on different autonomous levels of description. By focusing on the essence of a problem, coarse graining provides understanding. Nonequilibrium thermodynamics is employed to establish the thermodynamic consistency of any proposed level of description ("second law" and beyond). Nonequilibrium statistical mechanics is tailored into a practical tool to relate material parameters on different levels by efficient and systematic computer simulations thus overcoming the problems associated with the existence of a wide range of time scales in complex fluids, in particular, polymeric liquids. We develop theoretical foundations in the context of relevant systems.
A general thermodynamic framework should provide time evolution equations for bulk and boundary variables in terms of thermodynamic building blocks, such as energy and entropy. The bulk equations determine source terms in the equations for the boundary variables and, in turn, the boundary evolution equations provide boundary conditions for the bulk equations. more
In the context of solid state-based quantum information processing, external control in quantum optics, quantum transport through meso- and nanoscale structures, quantum tunneling in macroscopic systems, quantum Brownian motors, and biological reactions, for example, quantum dissipation is an important subject. We have proposed a general thermodynamic framework for dissipative quantum systems in weak contact with classical equilibrium and nonequilibrium environments. more
Nonequilibrium molecular dynamics and Brownian dynamics computer simulations are involved to solve the equations of motion for diluted or concentrated polymeric systems modeled by simple microscopic models such as ensembles of multibead chains. more
When investigating glasses, nonequilibrium phenomena are ubiquitous. We hence apply the modern framework of nonequilibrium thermodynamics to find out whether we might be able to raise our level of understanding of glasses, both from the conceptual and from the practical points of view. more