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Nanostructures
Possessing a structure comprising contiguous elements with one or more dimension in the nanoscale but excluding any primary atomic or molecular structure. NOTE 1. An example of a primary atomic or molecular structure is the arrangement of atoms in a crystalline solid. NOTE 2. The use of the term contiguous implies that a sphere of approximately 100 nm diameter, inscribed in a nanostructured material, will intersect more than one element of the structure. Source:
BSI. PAS 136:2007. Terminology for nanomaterials
A nanostructure is an object of intermediate size between molecular and microscopic (micrometer-sized) structures. In describing nanostructures it is necessary to differentiate between the number of dimensions on the nanoscale. Nanotextured surfaces have one dimension on the nanoscale, i.e., only the thickness of the surface of an object is between 0.1 and 100 nm. Nanotubes have two dimensions on the nanoscale, i.e., the diameter of the tube is between 0.1 and 100 nm; its length could be much greater. Finally, spherical nanoparticles have three dimensions on the nanoscale, i.e., the particle is between 0.1 and 100 nm in each spatial dimension. The terms nanoparticles and ultrafine particles (UFP) often are used synonymously although UFP can reach into the micrometre range. Source:
Wikipedia. Nanostructures
Various definitions of the dimensionality of nanostructures may be found in the literature. For example according to nanoscience and nanotechnologies report from the Royal Society and the Royal Academy of Engineering July 2004 [14]) nanostructures are divided into 3 classes:- Nanoscale in one dimension: thin films layers and surfaces
- Nanoscale in two dimensions: carbon nanotubes, inorganic nanotubes, nanowires, biopolymers
- Nanoscale in three dimensions: nanoparticles, fullerenes, dendrimers, quantum dots.
According to Łojkowski and Fecht classification in nanomaterials can be classified as follows: - (0-D) Nanoparticles, quantum dots, nanodots;
- (1-D) Nanowires, nanorods, nanotubes;
- (2-D) Coatings, thin-film-multilayers;
- (3-D) Bulk; Powders; Other nanostructures, including fractal structures.
Source:
Eighth Nanoforum Report: Nanometrology. July 2006
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