What makes nano interesting, promising and worrying at the same time is the fact that nano-size particles can have very different properties from the same material when it’s made of larger particles.

The material may be made of the same chemicals and the same molecules, but the small particle size increases the surface area, which can result in special properties. The properties may also vary depending on the shape or form. Some are just irregular shapes, while others have specific forms, such as tubes or balls.

Nano-particles can be manmade (engineered) or formed by nature or by accident. Smoke, for example, contains nano-particles, and an example of nano pollution is the release of tungsten nano-particles from tire studs.