Dispersion, distribution, and surface properties of different nanomaterials are among the most important factors that affect properties and functionalities of polymer nanocomposites. Therefore, a great amount of effort has been made to realize high-level uniform dispersion and precisely controlled distribution and surface properties of nanomaterials, in order to obtain desired dielectric properties, as discussed in the previous chapters.In addition to these efforts on a traditional composites, there are many new nanocomposite structures providing much potential for enhanced dielectric performances, thanks to the fast development of materials chemistry and physics, nanotechnology, and polymer processing technique.