Non-monotonic hydrodynamic lift force on highly extended polymers near surfaces

TitleNon-monotonic hydrodynamic lift force on highly extended polymers near surfaces
Publication TypeJournal Article
Year of Publication2011
AuthorsSing, CE, Alexander-Katz, A
JournalEpl
Volume95
Issue4
Date Published2011/08//
Abstract

The hydrodynamic lift force that polymers experience near boundaries is known to be a crucial element when considering rheological flows of dilute polymer solutions. Here we develop a theory to describe the hydrodynamic lift force on extended polymers flowing near flat surfaces. The lift force is shown to display a non-monotonic character increasing linearly with the distance to the wall Z in the near-surface regime defined as Z < L, with L being the contour length of the polymer. At heights Z similar to L the lift force displays a maximum, and for Z > L we recover the well-known far-field result in which the force decays as Z(-2). Our analytical theory has important implications in understanding adsorption, desorption, and depletion layers of highly extended objects in flow. Copyright (C) EPLA, 2011