Dynamical structure of entangled polymers simulated under shear flow

The non-linear response of entangled polymers to shear flow is complicated. Its current understanding is framed mainly as a rheological description in terms of the complex viscosity. However, the full picture requires an assessment of the dynamical structure of individual polymer chains which give r...

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Bibliographic Details
Published in:arXiv.org 2018-08
Main Authors: Korolkovas, Airidas, Gutfreund, Philipp, Wolff, Max
Format: Article
Language:English
Subjects:
Computer simulation
Melts
Nonlinear response
Polymer melts
Polymers
Rheological properties
Shear flow
Vorticity
Online Access:Get full text
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Summary:The non-linear response of entangled polymers to shear flow is complicated. Its current understanding is framed mainly as a rheological description in terms of the complex viscosity. However, the full picture requires an assessment of the dynamical structure of individual polymer chains which give rise to the macroscopic observables. Here we shed new light on this problem, using a computer simulation based on a blob model, extended to describe shear flow in polymer melts and semi-dilute solutions. We examine the diffusion and the intermediate scattering spectra during a steady shear flow. The relaxation dynamics are found to speed up along the flow direction, but slow down along the shear gradient direction. The third axis, vorticity, shows a slowdown at the short scale of a tube, but reaches a net speedup at the large scale of the chain radius of gyration.
ISSN:2331-8422
DOI:10.48550/arxiv.1703.10946