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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 59: Complex Fluids and Colloids, Micelles and Vesicles (joint session CPP/DY)
CPP 59.5: Vortrag
Mittwoch, 18. März 2020, 10:30–10:45, ZEU 114
Magnetically Functionalized Star Polymers in Equilibrium and under Shear — •Gerhard Kahl1, David Toneian1, and Christos N. Likos2 — 1Institut für Theoretische Physik, TU Wien — 2Fakultät für Physik, Universität Wien
Star polymers are macromolecules consisting of a central site, attached to which are a number f of linear polymer chains, called arms. Depending on the chemical composition of the arms, the polymer stars exhibit intriguing features, both in isolation and in concentrated solution.
We present star polymers with magnetically functionalized end groups as a novel polymeric system whose morphology, self-aggregation and orientation can easily be tuned by exposing these macromolecules simultaneously to an external magnetic field and to shear forces within a channel. Our investigations are based on a specialized simulation technique which faithfully takes into account the hydrodynamic interactions of the surrounding, Newtonian solvent. We find that the combination of magnetic field (including both strength and direction) and shear rate controls the mean number of magnetic clusters, which in turn is largely responsible for the static and dynamic behavior. While some properties are similar to comparable non-magnetic star polymers, others exhibit novel phenomena; examples of the latter include the breakup and reorganization of the clusters beyond a critical shear rate and a strong dependence of the efficiency with which shear rate is translated into whole-body rotations on the direction of the magnetic field.