Analysis of the Migration of Rigid Polymers and Nanorods in a Rotating Viscometric Flow


The dynamics and rheology of a rigid polymer or nanorod suspended in a Newtonian, viscous fluid under torsional flow have been studied. Our theoretical analysis predicts that rigid rods migrate in the radial direction according to their orientational configuration which is controlled by the competition between the shear flow, which tends to align the rods in the direction of flow, and Brownian motion, which tends to randomize the orientation. Steady and transient distributions of the center-of-mass in a dilute solution are derived from a kinetic theory and are confirmed by performing a Brownian dynamics simulation. The migration shifts the distribution toward the axis of rotation and enhances the shear-thinning behavior of the suspension.


Chemical and Biochemical Engineering

Keywords and Phrases

Axis of Rotation; Brownian Dynamics Simulations; Brownian Motion; Center-of-Mass; Dilute Solution; Newtonians; Orientational Configuration; Radial Direction; Rigid Polymers; Rigid Rods; Shear-Thinning Behavior; Steady and Transient; Viscometric Flows; Viscous Fluids; Brownian Movement; Nanorods; Rotation

International Standard Serial Number (ISSN)

0024-9297; 1520-5835

Document Type

Article - Journal

Document Version


File Type





© 2010 American Chemical Society (ACS), All rights reserved.

Publication Date

01 Mar 2010