Synergetic effects of interfacial and spatial confinement in polymer nanocomposites

Abstract

Dispersing three-dimensional (3D) nanoparticles as the filler into a polymeric component is known to significantly improve the physicochemical properties of the materials and makes them attractive for industrial applications. There are two main contributions to the underlying enhancement mechanism of polymer nanocomposites (PNCs). The first contribution is linked to the interfacial effect, originating from the interaction between polymer and nanoparticles. The packing density, conformation and orientation of adsorbed chains are significantly altered, which results in an interfacial region with different properties from the bulk. The second contribution is attributed to the spatial effect, introduced by confining polymer chains in a restricted space between/among nanoparticles. These two effects are often correlated. The characteristic behavior of polymer chains confined by nanoparticles has already shown to be quite complicated and hence interesting as compared with that of pure polymers. The broad range of influencing factors including the size, content and surface chemistry of nanoparticles as well as the molecular weight and chain ends of polymers were discussed in this review. The controversial issues such as the segmental dynamics at interface, interfacial architecture and the extent of its impact on the bulk phase were summarized, wishing to produce further understanding of PNCs.