Issue
EPL
Volume 86, Number 1, April 2009
Article Number 18002
Number of page(s) 5
Section Interdisciplinary Physics and Related Areas of Science and Technology
DOI http://dx.doi.org/10.1209/0295-5075/86/18002
Published online 17 April 2009
EPL, 86 (2009) 18002
DOI: 10.1209/0295-5075/86/18002

Rheological properties of polymer melt between rapidly oscillating plates: An application of multiscale modeling

S. Yasuda and R. Yamamoto

Department of Chemical Engineering, Kyoto University - Kyoto 615-8510, Japan and CREST, Japan Science and Technology Agency - Kawaguchi 332-0012, Japan

yasuda@cheme.kyoto-u.ac.jp

received 5 February 2009; accepted in final form 9 March 2009; published April 2009
published online 17 April 2009

Abstract
The behavior of supercooled polymer melt composed of short chains with 10 beads between rapidly oscillating plates is simulated by using a hybrid simulation of molecular dynamics and computational fluid dynamics. The flow profiles of polymer melt near an oscillating plate are quite different from those of Newtonian fluid. The viscous boundary layer of the melt is much thinner than that of the Newtonian fluid due to the shear thinning of the melt. Three different rheological regimes, i.e., the viscous fluid, viscoelastic liquid, and viscoelastic solid regimes, form over the oscillating plate according to the local Deborah numbers. The melt behaves as a viscous fluid when $\omega \tau ^{{\rm R}}\lesssim 1$, and the crossover between the liquid-like and solid-like regime takes place around $\omega \tau ^{\alpha}\simeq 1$ (where $\omega $ is the angular frequency of the plate, and $\tau ^{{\rm R}}$ and $\tau ^{\alpha }$ are the Rouse and $\alpha $ relaxation times, respectively).

PACS
83.60.Df - Nonlinear viscoelasticity.
83.10.Gr - Constitutive relations.
47.11.St - Multi-scale methods.

© EPLA 2009