What is Nanotechology?

Nanotechnology is the technology dealing with materials, devices and systems with structures in the size range of 1 to 100 nm. (1 nm = 10-9 m) Nanotechnology involves nearly all fields of natural science including material science, engineering, chemistry, applied physics and life science. Until now no clear definitions have been found due to the interdisciplinary origin of nanotechnology. To give an example: while spherical particles with a diameter of 100 nm are termed nanoparticles in material science, similar particles are termed colloids in colloidal science and toxicologists term such a material ultrafine particles.

A terminology for nanotechnology and different nanomaterials is proposed below.

Notation

Nanotechnology deals with materials, devices and systems with structures in one dimension between 1 and 100 nanometers.

Nanomaterials have two axes or dimensions in the size range of 1 to 100 nm, e.g. carbon nanotubes, spherical nanoparticles, nanorods.

Nanoparticles are a subclass of nanomaterials which have all three axes or dimensions in the size of 1 to 100 nm.

Production of nanomaterials

Nanoparticles can be produced by accident or on purpose. Engineered materials differ strongly from particles obtained unintendedly, e.g.from brake wear or automotive combustion processes. Two different approaches can be differentiated to obtain nanomaterials or nanoparticles. The “bottom-up” approach employs molecular components or ions which grow according to chemical or physical principles. In contrast, the “top-down” approach uses bulk materials which are then reduced in size to form nanomaterials or nanoparticles, for example by milling.