Nanoscience is the field of science that focuses on the study of nanoparticles, which are incredibly small particles that have a diameter of 1 to 100 nanometers. This size is so small that it cannot be seen with the naked eye or even under a light microscope. In fact, nanoparticles contain only a few hundred atoms.

  • To put it into perspective, a nanometre is 1 billionth of a metre, or 1×10-9 m

This small size makes nanoparticles much smaller than even the finest particles, and significantly smaller than coarse particles. The table below compares the size of nanoparticles to coarse particles and fine particles.

ParticleDiameter (nm)
NanoparticlesBetween 1 and 100
Fine particlesBetween 100 and 2,500
Coarse particlesBetween 2,500 and 10,000

Surface Area to Volume Ratio

As things get smaller, their volume decreases at a faster rate than their surface area. For this reason, nanoparticles have a large surface area-to-volume ratio.

For example, as the size of a cube decreases by a factor of 10, the surface area to volume ratio increases by a factor of 10.

The surface area = \dfrac{Surface\:area}{Volume}