Experimental Soft Matter Group

Permanent URI for this community

We are interested in the physics of soft condensed matter, in particular in the non-equilibrium behaviour of these systems. This mainly concerns three generic situations: Application of external fields. The presence of even small forces or potentials can result in significant changes in the arrangement and dynamics of colloidal dispersions (hence soft matter). We study the effect of bulk mechanical forces (shear) and spatially varying potentials, which we generate optically (similar to optical tweezers). Relaxation to an equilibrium or long-lived metastable state following a change in a thermodynamic parameter, such as concentration, composition or temperature. The actual processes can be as different as the crystallization of colloids or the self-assembly and self-organization of surfactant aggregates as well as their structural transformations. Flow of solvent and solutes through porous matrices. This includes imbibition and diffusion of a solvent through solid matrices as well as the swelling and dissolution of polymer or surfactant systems after contact with a solvent, which might contain particles. Although we mainly study colloidal systems, we are also interested in surfactants and polymers. These systems are experimentally investigated using different measurement techniques, including conventional and confocal microscopy, static and dynamic light scattering, rheology, neutron imaging as well as neutron and x-ray scattering.