The most significant characteristic of nanocomposites is the large interface between the polymer and nano-fillers, which strongly affects the properties of these materials. Moreover, many combinations of polymer and nano-fillers provide many kinds of nanocom-posites. As an introduction to the fabrication of nanocomposites, this section compares nano-filler and micro-filler interfaces within a polymer and examines how polymers and nano-fillers can be combined to improve properties. 3.1.1 Large Interface of Nano-Fillers

Nano-fillers have large interfaces with the surrounding polymer compared, to micro-filled systems. For example, when nano-fillers or micro-fillers with the same filler content are disperse into a polymer, the polymer/filler interface area per unit volume, calculated according to the following formula, are very different [1]:

Polymer/filler interface area per volume unit = 6D____f,where D is the diameter of the filler and f the volume fraction of the filler.