Nanotechnology Lect.8

Composites
The idea behind nanocomposites is to use building blocks with dimensions in the nanometre range to design and create new materials with unprecedented flexibility and improvements in their physical properties. This concept is exemplified in many naturally occurring materials, such as bone, which is a hierarchical nanocomposite built from ceramic tablets and organic binders. When designing the nanocomposite, scientists can choose constituents with different structures and composition and, hence, properties, so that materials built from them can be multifunctional.
As a general definition, a nanocomposite is a conventional material reinforced by nanoscale particles or nanostructures which are dispersed throughout the bulk material. The base material itself generally consists of non-nanoscale matrices. Nanocomposites typically consist of an inorganic (host) solid containing an organic component or vice versa or two (or more) inorganic/organic phases in some combinatorial form. At least one component must be nano-sized. In general, nanocomposite materials can demonstrate different mechanical, electrical, optical, electrochemical, catalytic and structural properties which are different from those of the individual components. Apart from the properties of the individual components, interfaces in a nanocomposite play an important role in determining the overall properties of the material. Due to the high surface area of nanostructures, nanocomposites present many interfaces between the intermixed phases and, often, the special properties of the nanocomposite are a consequence of the interaction of its phases