A Self-Consistent Field Study of Interfacial Dynamics in Unentangled Homopolymer Fluids in a Sheared Channel

Abstract

In a preceding paper, we have presented a general lattice formulation of the dynamic self-consistent field (DSCF) theory for inhomogeneous, unentangled homopolymer fluids. Here we apply the DSCF theory to study both transient and steady-state interfacial structure, flow and rheology in a sheared planar channel containing either a one-component melt or a phase-separated, two-component blend. We focus here on the case that the solid-liquid and the liquid-liquid interfaces are parallel to the walls of the channel, and assume that the system has translational symmetry within planes parallel to the walls. This symmetry allows us to derive a simplified, quasi-one-dimensional (quasi-1D) version of the DSCF evolution equations for free segment probabilities, momentum densities, and the ideal-chain conformation tensor. Numerical solutions of the quasi-1D DSCF equations are used to study both the transient evolution and the steady-state profiles of composition, density, velocity, chain deformation, stress, viscosity and normal stress within layers across the sheared channel. Good qualitative agreement is obtained with previously observed phenomena.