Complex Fluids in Restricted Geometry
- Source: Ralf Biehl FZ Jülich
Prof. Hans-Jürgen Butt (MPI Polymer Research)
Prof. Burkhard Dünweg (MPI Polymer Research)
Prof. Thomas Palberg (FB08, Physics)
Prof. Friederike Schmid (FB08, Physics)
When mesoscale particles like macromolecules, drug-carriers, fibres or colloidal spheres are immersed in a carrier fluid, a so-called Complex Fluid emerges which displays fascinating mechanical and optical properties not seen in the constituents. In particular, suspensions of colloidal spheres or rods form fluid or (liquid-)crystalline ordered states once the range and strength of interaction between the colloidal particles becomes sufficiently large and long-ranged. Their equilibrium properties are meanwhile quite well understood. However, without a decent understanding also of the non-equilibrium properties and the influence of confinement to small system sizes, no controlled application will become possible.
Questiones touched here comprise freezing and melting in small pores, yielding of materials under strong load, shear induced ordering or microfluidic transport of drug carriers. The MPGC joins experimental and theoretical expertise to address such problems by complementary approaches from theory, simulation and experiment.
The interplay of long-range hydrodynamic and electrostatic interactions with confinement effects leads to a wealth of intriguing phenomena which are a challenge to simulation approaches. The MPGC provides an excellent environment for the development of new efficient methods to solve this problem and their application e.g. to electrophoresis and dielectrophoresis. The making and manipulation of structures with defined optical properties on the other side is subject of experimental studies employing shear, electric fields and restricting geometry, e.g. systems confined in narrow slits or capillaries.
The intense collaboration and exchange between the complementary approaches within this Centre provides a fertile ground for advancing our understanding and control of the fundamental physics governing the fascinating properties of Complex Fluids.