Migration of nanoparticles across a polymer-polymer interface: theory and simulation.

We proposed recently a theoretical description for hydrodynamic flows in inhomogeneous liquids in the vicinity of solid interfaces, consistent with current theoretical descriptions of the thermodynamical equilibrium of liquids in the vicinity of solid surfaces and with the Onsager formalism for linear response theory in out-of-equilibrium liquids. We showed that these equations allow for describing diffusio-osmosis along a capillary and also wetting/dewetting dynamics of liquids on a solid substrate. We now apply this physical model to the wetting/dewetting dynamics of nano-particles in polymer blends, showing how they reach equilibrium at the interface between two liquids at rest and how they migrate from the non-preferred polymer to the preferred one under applied flow.