This paper shows preliminary results for polymer nanocomposites consisting of “hairy” silica particles with grafted polystyrene in polystyrene matrices of controlled molecular weight and polydispersity. The goal of the work is to tailor the degree of wetting / interaction between the particles and polymer by controlling the graft density and molecular weight of the grafted polymer. This is providing an opportunity to study the properties of the interface region and to control the bulk composite properties. We have found that the predictions for flat brushes are qualitatively, but not quantitatively, applicable and that the highly curved surfaces of nanoparticles present several challenges for the design of nanoparticle interfaces. The talk will present more complete results in this system and provide an overview of other work in our group using tailored interfaces to control nanocomposite properties.