Fluids of semiflexible ring polymers: effective potentials and clustering

Autor(en)

Marco Bernabei, Petra Bacova, Angel J. Moreno, Arturo Narros, Christos Likos

Abstrakt

We present a computational investigation of the structural properties of a fluid of semiflexible ring polymers. Stiffness is introduced by implementing intramolecular barriers. Because of these barriers, shrinkage of the rings is energetically unfavourable, and the ring size can exhibit a non-monotonic density dependence. At high concentrations the rings can swell and adopt open configurations that facilitate interpenetration and clustering. We obtain effective potentials between the centers-of-mass of the rings at infinite dilution, and explore their validity over the whole range of concentrations. Except for the limit of small rings, the effective fluid of ultrasoft particles provides a good description of the real system over a considerable range of densities, even above the overlap concentration. In particular the clustering behaviour predicted by the effective description is observed in the real system for a certain range of molecular masses. However, the effective description is incomplete. Inspection of the clusters of real rings reveals that these can arrange in a complex disordered phase formed by long columns of oblate rings, which are penetrated by bundles of elongated prolate rings. These anisotropic features of the real system are not captured by the standard effective approach, which only considers macromolecular centers-of-mass. This suggests the need to include the relative orientation between rings in the effective potentials.

Organisation(en)

Computergestützte Physik und Physik der Weichen Materie

Externe Organisation(en)

Donostia International Physics Centre (DIPC), University of the Basque Country

Journal

Soft Matter

Band

9

Seiten

1287-1300

Anzahl der Seiten

14

ISSN

1744-683X

DOI

https://doi.org/10.1039/C2SM27199K

Publikationsdatum

2013

Peer-reviewed

Ja

ÖFOS 2012

103036 Theoretische Physik, 103029 Statistische Physik

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/5c11c238-2f06-4c17-a374-b7238e6ca759