Dr. Kurt Kremer
"Topological Constraints Matter: Elastomers , Collapsed Polymer Globules, Chromosome Territories"
December 1, 2011
4:05pm | New Physics Building 1002
Professor Dr. Kurt Kremer, the Director of the Max Planck Institute for Polymer Research in Mainz, Germany, presented a seminar in the New Physics Building room 1002. Dr. Kremer is a world authority in his field.
The role of topological constraints on conformational as well as relaxational and dynamical properties of open linear and closed ring polymers as well as mixtures thereof is discussed. In the case of polymer melts the conformational statistics can be used to directly determine the entanglement molecular weight in excellent agreement to experiment. By manipulating the entanglements in long chain melts materials with new rheological properties can be achieved. For ring polymers the situation is completely different. While linked rings act like DeGennes' Olympic gels, we find that non concatenated polymer rings segregate and form individual "collapsed" objects. I discuss some details of their conformations, which not only is related to one of the very basic problems in polymer science but also has far reaching consequences from the collapse of gels to chromosome territories.