Monte Carlo simulation of self-avoiding lattice chains subject to simple shear flow Part II. Three-dimensional results and comparison with experiments

This paper has extended a lattice Monte Carlo (MC) method to simulate the s imple shear flow of multiple self-avoiding chains in three dimensions follo wing our research work in two dimensions. Comparisons of simulation outputs with experimental observations, theoretical predictions and other simulati on results are made. The steady-stare scaling analysis to scattering functi ons of deformed chains confirms the existence of anisotropic scaling laws a t fixed reduced shear rates found in molecular dynamics (MD) simulation. Th e exponent of chain deformation shown in the MC simulation falls into a nor mal regime measured from neutron scattering and light scattering experiment s. The relation between orientation angles and shear rates is consistent wi th some scattering experiments. Both Newtonian and non-Newtonian regimes ar e reproduced in our lattice MC simulation. Non-zero first and second normal stress differences and their dependence of the shear rate are found, as we ll as the shear thinning effect. The stress growth at inception and stress decay after cessation of shear flow is also examined. The validity of our n ovel simulation approach is thus confirmed. Since both chain conformations and rheological properties under shear flow can be studied, our MC approach can be used to reveal non-linear viscoelasticity of polymer fluids and pol ymer-flow interaction. (C) 2000 Elsevier Science Ltd. All rights reserved.