Dense brushes of stiff polymers or filaments in fluid flow

Theoretical Soft Matter and Biophysics, Institute of Complex Systems and Institute for Advanced Simulation, Forschungszentrum Jülich - 52425 Jülich, Germany

Received: 18 November 2014
Accepted: 2 March 2015

Abstract

Dense filamentous brush-like structures are present in many biological interfacial systems (e.g., glycocalyx layer in blood vessels) to control their surface properties. Such structures can regulate the softness of a surface and modify fluid flow. In this letter, we propose a theoretical model which predicts quantitatively flow-induced deformation of a dense brush of stiff polymers or filaments, whose persistence length is larger or comparable to their contour length. The model is validated by detailed mesoscopic simulations and characterizes different contributions to brush deformation including hydrodynamic friction due to flow and steric excluded-volume interactions between grafted filaments. This theoretical model can be used to describe the effect of a stiff-polymer brush on fluid flow and to aid in the quantification of experiments.