Slip boundary conditions for shear flow of polymer melts past atomically flat surfaces

Abstract

Molecular dynamics simulations are carried out to investigate the dynamic behavior of the slip length in thin polymer films confined between atomically smooth thermal surfaces. For weak wall-fluid interactions, the shear rate dependence of the slip length acquires a distinct local minimum followed by a rapid growth at higher shear rates. With increasing fluid density, the position of the local minimum is shifted to lower shear rates. We found that the ratio of the shear viscosity to the slip length, which defines the friction coefficient at the liquid/solid interface, undergoes a transition from a nearly constant value to the power law decay as a function of the slip velocity. In a wide range of shear rates and fluid densities, the friction coefficient is determined by the product of the value of surface induced peak in the structure factor and the contact density of the first fluid layer near the solid wall.

27 pages, 11 figures

References in corpus (3)

• Rate-dependent slip boundary conditions for simple fluids
• Effect of surface roughness on rate-dependent slip in simple fluids
• Comparison of Dissipative Particle Dynamics and Langevin thermostats for out-of-equilibrium simulations of polymeric systems

Cited by in corpus (6)

• Shear rate threshold for the boundary slip in dense polymer films
• The relationship between induced fluid structure and boundary slip in nanoscale polymer films
• Molecular dynamics simulations of oscillatory Couette flows with slip boundary conditions
• Rheological study of polymer flow past rough surfaces with slip boundary conditions
• Interfacial friction between semiflexible polymers and crystalline surfaces
• Multiscale Approach to Fluid-Solid Interfaces: An overview of methodologies coupling fluid mechanics to molecular dynamics and quantum theory