‘Nano’ refers to something that is very small. A nanometer (nm) is one billionth of a metre while a nanosecond is one billionth of a second.
Because nano particles are so small, they have very special properties. The small size effects their physical properties, like their surface area, magnetic properties, melting point and electrical conductivity. Their size also effects their quantum properties – quantum confinement, discrete states, superpositions, and entanglement.
An example of how this effects them is their surface area – they have an extremely large surface area compared to their size. This is important as it means they have large reactive surfaces for things like catalysis, absorption and other processes.
When you combine nano particles with other materials, they lend their special properties to those materials forming exciting new substances.
Nanotechnology involves using the special properties of nano particles. Some definitions are:
- Nanoscience is the study and discovery of these new properties. It is a multidisciplinary field involving physics, chemistry and biology
- Nanotechnology is the use of these new properties in special products and applications
Nanotechnology creates new materials that have applications across a variety of industries, for example, creating biomarkers used in medical diagnosis, creating very sensitive sensors that have a variety of applications, creating catalysts that can radically change the rate of a reaction, and creating strong and light new materials.
These are tiny particles that have a very large surface area compared to their size ( >400m2/gm) that have magnetic properties, ductility and formability, and are important in catalytic activity. They have various uses including in catalysts, creating flexible electronics, and in solar cells.
These are rolled up carbon sheets that behave like metal or semiconductors. They conduct electricity and heat extremely well, are 100x stronger than steel but only weigh one sixth the weight of steel. If you combine them with other materials, you can get materials that are very strong and light and that have great conductive properties.
Quantum dots are tiny tiny crystals that are semiconductors. They are special because their conducting abilities are closely related to their size and shape. This means that different quantum dots emit different colour light when they are excited. This makes them extremely useful in a number of applications such as biomarkers, sensors, in special coatings, solar cells and diode lasers.
Nanocomposites are made by combining a number of materials together including nanoparticles, where the resultant material has properties that differ widely from that of the component materials. The nanoparticle greatly influences the properties of the resultant composite.
http://www.sani.org.za South African Nanotechnology Initiative
http://www.trynano.org TryNano.org – about nanotechnology and nanoscience
http://www.newscientist.com/topic/nanotechnology The New Scientist’s portal on nanotech, including news items and articles
http://www.crnano.org/whatis.htm Center for Responsible Nanotechnology