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

作者：Sing C E^*; Alexander Katz A

来源：EPL, 2011, 95(4): 48001.

DOI：10.1209/0295-5075/95/48001

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.

• 出版日期2011-8