Enhanced Structure at the Interface Between the Polymer Matrix and Spherical Nanoparticles in Polymer Based Nanocomposites

摘要

The effect of a curved solid wall on the conformations of long, flexible polymer chains is studied in a dense polymer system by means of lattice Monte Carlo simulations. The differences with respect to the flat interface case are discussed. In the athermal limit the wall does not perturb the atom number density, which is constant throughout the volume of the polymer, however the chain end density is higher at the wall compared to the bulk and the bonds are preferentially oriented parallel to the interface. The intensity of these effects decreases with increasing wall curvature. These conclusions preserve qualitatively in presence of energetic interactions. The density at the wall decreases and the chain end segregation increases with increasing cohesive energy in the bulk polymer. The chain mobility is much lower in the close vicinity of the wall compared to the bulk. This effect increases with increasing wall curvature, which suggests that the experimentally observed reduction in chain mobility with filler radius has, in part, an entropic origin.