A Multichain Slip-Spring Dissipative Particle Dynamics Simulation Method for Entangled Polymer Solutions

Abstract

We have extended a recently developed multichain slip-spring approach to polymer solutions. The method is based on the dissipative particle dynamics (DPD). Entanglements are mimicked by the inclusion of slip-springs that connect polymer beads, slide along their contour, and are created/destroyed at chain ends. The required average number of slip-springs in polymer melts can be adjusted by the chemical potential. In solutions, we assume that the chemical potential and the friction of slip-springs are constant regardless of the polymer volume fraction. We have evaluated the proposed method by a comparison with experimental data. For this purpose, we have performed dynamic viscoelastic measurements for polystyrene/tricresyl phosphate solutions. The linear viscoelastic spectra are in reasonable agreement including the plateau modulus given that the comparison is made for a reduced frequency normalized by the Rouse time. The dependence of the slip-spring friction and the chemical potential of slip-springs on the polymer volume fraction may be considered for further improvement of the model.