Nanoscience nanometer size scale

Nanoscience involves materials where some critical properly is attributable to a structure with at least one dimension limited to the nanometer size scale, 1 -100 nanometers . Below that size die disciplines of Chemistry and Atomic/Molecular Physics have already provided detailed scientific understanding. Above that size scale, in the last SO years Condensed Matter Physics and Materials Science have provided detailed scientific understanding of microstructures. So die nanoscale is the last size fixintier for materials science. 

If one expected to sinq)ly extrapolate the properties of nanostructures from the size scales above or below, then there would be little reason for the current interest in nanoscience/nanotechnology. There are three reasons for nanostructured materials to behave very differently large surface/interface to volume ratios, size effects (where cooperative phenomena like ferronmgnetism is con romised by the limited number of atoms/molecules) and quantum effects. Many of the models for nmterials properties at the micron and larger sizes have characteristic length scales of nanometers (see Table II). When the size of the structure is nanometer, diose paran ters will no longer be adequate to model/predict the property. One can expect surprises - new materials behavior that may be technologically exploitable. 

Composites are widely used in such diverse areas as transportation, construction, electronics and consumer products. They offer unusual combinations of stiffness, strength and weight that are difficult to attain separately from the individual components. The advent of nanoscience and nanotechnologies has continuously provided the impetus pushing for the development of materials with fascinating properties and a rich variety of applications. Polymer-clay (PC) nanocomposites represent a new class of materials based on reinforcement of polymeric materials by dispersion of nano-scale clay particles at molecular level in the polymer matrix. Because of their nanometer size features, nanocomposites possess unique properties typically not shared by their more conventional miaocomposite counterparts and therefore offer new technology and business opportunities. 

There is another important concept embodied in the term nanostructure it is of great relevance in catalytic applications. As a conseqnence of the widespread (and somewhat unfortunate) nse of the terms nanocarbons and nanoporous carbons, it was discussed by Inagaki and Radovic [26] Nanocarbons are carbon materials produced when either their size or their strnctnre is controlled at the nanometer scale. It is therefore fine that nanotechnology and nanoscience were bom in the wake of the discovery of fnllerenes and nanotnbes, with enthusiastic support of the media fascinated by their beanty [3,27,28] bnt many of the classical (flat sp -hybridized) carbons are also nanomaterials becanse we have learned how to control either their nano-strnctnre or their nano-size, or both ... 

Nanoscience is the study of the world on the nanometer scale, from approximately one to several hundred nanometers (i). One nanometer (nm) is one billionth of a meter. To put this into perspective, a human hair is approximately 50,000 nm in diameter, the individual components of computer chips are about 65 nm in size and a DNA molecule is 2.5 nm wide. Nanotechnology is the manipulation of molecules and atoms on the nanoscale and fabrication of nanoscale devices. The potential benefits of nanoscience and nanotechnology span diverse areas, including nanoelectronics, medicine, the enviromnent, chemical and pharmaceutical industries, agriculture, biotechnology and computation. 

---