Polymer dynamics in linear mixed flow

Dua, Arti and Cherayil, Binny J (2003) Polymer dynamics in linear mixed flow. In: Journal of Chemical Physics, 119 (11). pp. 5696-5700.

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Abstract

Recent simulations by Chu et al. [Phys. Rev. E 66, 011915 (2002)] on the behavior of bead–spring and bead–rod models of polymers in linear mixed flows (flows with unequal amounts of extension and rotation) are compared with the predictions of a finitely extensible Rouse model that was used earlier [J. Chem. Phys. 112, 8707 (2000)] to describe the behavior of long flexible molecules of \lambda-phage DNA in simple shear. The model is a generalization of the continuum Rouse model in which the "spring constant" of the bonds connecting near neighbor segments is allowed to become nonlinearly flow-dependent through a term involving the initially unknown mean square size of the chain, [R2]. A self-consistent equation for this quantity is derived by using the flow-modified Hamiltonian to calculate it from its statistical mechanical definition. After solving this equation numerically, the mean fractional extension of the chain x can be obtained as a function of the Weissenberg number Wi and a mixing parameter \alpha. The results compare favorably with data from the simulations of Chu et al., and suggest the existence of a scaling variable Wieff = \sqrt{\alpha} Wi in terms of which separate curves of x versus Wi fall more or less on a single universal curve.

Item Type:	Journal Article
Publication:	Journal of Chemical Physics
Publisher:	American Institute of Physics
Additional Information:	Copyright for this article belongs to American Institute of Physics (AIP).
Department/Centre:	Division of Chemical Sciences > Inorganic & Physical Chemistry
Date Deposited:	13 Jan 2005
Last Modified:	19 Sep 2010 04:17
URI:	http://eprints.iisc.ac.in/id/eprint/2640

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