Prof. Walter Richtering, Institute of Physical Chemistry, RWTH Aachen

Microgels as responsive ingredients in bulk and at interfaces

Special Seminar

Multi-sensitive microgels have special properties that can be controlled via the chemical composition as well as the morphology of the particle. 

We will discuss the incorporation of responsive microgels into hydrogels. This leads to composite gels that are suitable as model systems for 3-dimensional cell cultures. The structure of these composite gels is probed by small angle neutron scattering as well as by confocal fluorescence microscopy revealing information on the temperature-sensitivity of embedded microgel particles. We will discuss whether or not interpenetrating networks are formed. In addition the diffusion of tracer molecules was investigated by means of 2-focus fluorescence correlation spectroscopy, which allows for spatially resolved tracer diffusion measurements in complex, crowding environments.

The second part of the talk is concerned with the unique behavior of microgels at fluid interfaces. Microgels are used to prepare stimuli-sensitive emulsions, the stability of which can be made pH- and temperature sensitive. However, these emulsions are distinctly different from Pickering emulsions stabilized by rigid particles. With microgels it is even possible to prepare stable emulsions with oppositely charged droplets. We report on interfacial properties of microgels with different co-monomer composition and different architecture. Fundamental aspects of structure and dynamics are probed e.g. by cryogenic electron microscopy and rheology. Finally we discuss applications in biocatalysis.

For more information contact Prof. Andrew Lyon (404-894-4090).

Website:  Prof. Walter Richtering