Interfacial friction between semiflexible polymers and crystalline surfaces

Abstract

The results obtained from molecular dynamics simulations of the friction at an interface between polymer melts and weakly attractive crystalline surfaces are reported. We consider a coarse-grained bead-spring model of linear chains with adjustable intrinsic stiffness. The structure and relaxation dynamics of polymer chains near interfaces are quantified by the radius of gyration and decay of the time autocorrelation function of the first normal mode. We found that the friction coefficient at small slip velocities exhibits a distinct maximum which appears due to shear-induced alignment of semiflexible chain segments in contact with solid walls. At large slip velocities the decay of the friction coefficient is independent of the chain stiffness. The data for the friction coefficient and shear viscosity are used to elucidate main trends in the nonlinear shear rate dependence of the slip length. The influence of chain stiffness on the relationship between the friction coefficient and the structure factor in the first fluid layer is discussed.

31 pages, 12 figures

References in corpus (13)

• Equilibration of Long Chain Polymer Melts in Computer Simulations
• Slip behavior in liquid films on surfaces of patterned wettability: Comparison between continuum and molecular dynamics simulations
• Influence of wetting properties on the hydrodynamic boundary condition at a fluid-solid interface
• Rate-dependent slip boundary conditions for simple fluids
• Effect of surface roughness on rate-dependent slip in simple fluids
• Modeling the combined effect of surface roughness and shear rate on slip flow of simple fluids
• Temperature dependence of the slip length in polymer melts at attractive surfaces
• Molecular diffusion and slip boundary conditions at smooth surfaces with periodic and random nanoscale textures
• Shear rate threshold for the boundary slip in dense polymer films
• Slip boundary conditions for shear flow of polymer melts past atomically flat surfaces
• The relationship between induced fluid structure and boundary slip in nanoscale polymer films
• Statics and dynamics of a cylindrical droplet under an external body force
• Rheological study of polymer flow past rough surfaces with slip boundary conditions

Cited by in corpus (2)

• Molecular dynamics simulations of oscillatory Couette flows with slip boundary conditions
• Multiscale Approach to Fluid-Solid Interfaces: An overview of methodologies coupling fluid mechanics to molecular dynamics and quantum theory