Nanorod diffusion in polymer nanocomposites by molecular dynamics simulations

Nanorod diffusion and polymer dynamics in nanocomposites were investigated by means of molecular dynamics simulations. We show that thin nanorods (spherocylinders) can diffuse much faster than that predicted by a Stokes–Einstein continuum model, similar to experiments, in the dilute nanorod regime. In entangled polymer matrices, nanorod diffusion reaches a plateau region. Increase of the nanorod diameter or aspect ratio (AR) slows its diffusion. The nanorod diffusion, at long time scales, displays a non-Gaussian behavior as is depicted by the several Gaussian peaks present in the self-part of the van Hove function. We also show that the unentangled polymer dynamics decreases in the nanocomposite due to the nanorods interfacial area.