Distinguished Seminar Series 2021 | Professor Walter Richtering

Abstract: Microgels are macromolecular networks swollen by the solvent they are dissolved in. They are unique systems that are distinctly different from common colloids, such as, e.g., rigid nanoparticles, flexible macromolecules, micelles or vesicles. When swollen, they are soft and have a fuzzy surface with dangling chains and the presence of cross-links provides structural integrity – in contrast to linear and (hyper-) branched polymers. Finally, microgels reveal interface activity without being amphiphilic. Due their properties, microgels can be used to tune the colloid-to-polymer transition. We will discuss properties of stimuli-sensitive microgels of different architecture (as e.g. ultra-low crosslinked, hollow, multi-shell) both in aqueous solution and at interfaces. One the one hand, these microgels are model systems to study soft matter physics; on the other hand, they provide unique features for various applications. The structure of microgels is investigated by means of scattering methods, especially exploiting the technique of contrast variation in small angle neutron scattering as well as by scanning force and super-resolved fluorescence microscopy. The experimental results will be compared to computer simulations.