Mesoscopic Simulation of Entangled Polymer Brushes under Shear: Compression and Rheological Properties

Abstract

We report a study of the influence of chain entanglements in dissipative particle dynamics simulations of polymer brushes under shear. We observe that the incorporation of an entanglement potential to prevent bond crossings significantly changes the friction and viscosity of these systems. Simulations have been carried out for different compression ratios at constant chemical potential. We have also studied the influence of the solvent quality and the intensity of the shear rate on the thermodynamic, structural, and rheological properties of the system. We show that the behavior of the model polymers is in good agreement with SFA experiments and theoretical scaling laws. The use of an entanglement potential avoids the artificial overlap between polymer particles that often occurs on the mesoscopic scale. We conclude that such a model is necessary for the correct description of the polymer brush system, especially for the calculation of rheological and frictional properties.