Nanoparticle-Induced Hydrodynamic Flows in Unentangled Polymer Melts

We measured the flow induced by nanoparticles in unentangled polymer melts by computing displacement correlations between nanoparticles and polymer beads in coarse-grained molecular dynamic simulations. Contrary to conventional assumptions, which consider the induced flow to be exponentially screened, we find that nanoparticles propagate long-range flows with a slow algebraic decay. An analytical theory for nanoparticle-induced flow is developed by combining polymer scaling theory and fluid mechanics. The model agrees with simulation data and provides a framework to determine the role of hydrodynamic flows in the interpretation and prediction of nanocomposite properties.