Regensburg 2019 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 67: Polymer and Molecular Dynamics, Friction and Rheology
CPP 67.6: Vortrag
Freitag, 5. April 2019, 11:15–11:30, H13
Filtering polymeric topologies in spatially-modulated nano channels — •Lisa B. Weiss1, Mattia Marenda2, Cristian Micheletti2, and Christos N. Likos1 — 1Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria — 2SISSA, International School of Advanced Studies, via Bonomea 265, I-34136 Trieste, Italy
Polymers of various topologies are of importance in biology, rheology and material science. Macromolecules of distinct topology consist of the same type and number of monomers, making it challenging to separate them using chemical approaches. Nevertheless, topology influences strongly their response to flow fields in concentrated and dilute solutions. Previously, successful separation strategies for linear and circular polymers have been developed, which unfortunately fail in the case of knotted ring polymers. Thus, we present a novel separation strategy employing spatially-modulated channels, building up on topology-dependent diffusivities in such channels. We take hydrodynamic interactions via the multi-particle collision algorithm into account. In equilibrium, we find an astonishing inversion of diffusivities in modulated channels compared to bulk, which can be rationalized by a Fick-Jacobs approach. Applying a flow enables a reliable separation of circular polymers from their knotted counter parts in weak flows. Looking in detail at the relevance of the size of the narrowing, we identify a regime of strong restrictions on polymer translocations in the case of pore sizes smaller than the average knot size. Here, the essential crossings act as a parachute preventing translocation.