Regensburg 2019 – wissenschaftliches Programm
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DY: Fachverband Dynamik und Statistische Physik
DY 55: Poster: Noneq. Stat. Phys., Stat. Bio. Phys., Brownian
DY 55.2: Poster
Donnerstag, 4. April 2019, 15:00–18:00, Poster B2
Coarse-grained toy model for ring polymer melts — •Stanard Mebwe Pachong1, Jan Smrek2, and Kurt Kremer1 — 1Max Planck Institute for Polymer Research, Mainz, Germany — 2University of Vienna, Austria
Nonconcatenated and unknotted rings in melt subdiffuse on length scales several times larger than their gyration radius [1]. It has been hypothesised that ring threadings [2,3], although they might be quantitatively marginal [4]. On the other hand, the prolonged onset of diffusion can be observed also in a dense system with a small number of particles with a relatively deep correlation hole. Due to a finite-size effect, a significant rearrangement would be necessary for large particle displacements which results in longer sub-diffusion regime. As the simulated ring melts [1] were composed of only 200 rings and have deep correlation holes, the effect can be at play. In order to understand the cause of the subdiffusion of the rings melt, we attempt to falsify the threading hypothesis. We constructed a simple coarse-grained (soft-sphere) model of rings that (trivially) cannot thread, but can exhibit the correlation hole effect. We have not found a sign of subdiffusion. This goes in line with a recent observation that threading and diffusion relax on similar time scales[4].
References
[1] J. D. Halverson et al., J. Chem. Phys., 134,204905(2011) [2] Michieletto et al. ACS Macro Lett.,3,255-259(2014) [3] J. smrek and A. Y. Grosberg,ACS Macro Lett.5,750-754(2016) [4] J. Smrek, K. Kremer, A. Rosa ,unpublished(2018)