Cyclic motion and inversion of surface flow direction in a dense polymer brush under shear

Abstract

Using molecular simulations, we study the properties of a polymer brush in contact with an explicit solvent under Couette and Poiseuille flow. The solvent is comprised of chemically identical chains. We present evidence that individual, unentangled chains in the dense brush exhibit cyclic, tumbling motion and non-Gaussian fluctuations of the molecular orientations similar to the behaviour of isolated tethered chains in shear flow. The collective molecular motion gives rise to an inversion of hydrodynamic flow direction in the vicinity of the brush-coated surface. Utilising Couette and Poiseuille flow, we investigate to what extend the effect of a brush-coated surface can be described by a Navier slip condition.

6 pages, 6 figures, submitted for publication

References in corpus (4)

• Static and dynamic properties of the interface between a polymer brush and a melt of identical chains
• Statistics of tumbling of a single polymer molecule in shear flow
• Comparison of Dissipative Particle Dynamics and Langevin thermostats for out-of-equilibrium simulations of polymeric systems
• Interfacial Slip in Sheared Polymer Blends

Cited by in corpus (10)

• Temperature dependence of the slip length in polymer melts at attractive surfaces
• Correlation between surface topography and slippage: a Molecular Dynamics study
• Polymer brush collapse under shear flow
• Molecular transport and flow past hard and soft surfaces: Computer simulation of model systems
• Statistics of polymer adsorption under shear flow
• Equilibrium measurement method of slip length based on fluctuating hydrodynamics
• Brushes of semiflexible polymers in equilibrium and under flow in super-hydrophobic regime
• Droplet transport in a nanochannel coated by hydrophobic semiflexible polymer brushes: the effect of chain stiffness
• Shear deformation of low-density polymer brushes in a good solvent
• Entropic stress of grafted polymer chains in shear flow