In nanotechnology, a particle is defined as a small object that behaves as a whole unit in

terms of its transport and properties. It is further classified according to size In terms of diameter, fine

particles cover a range between and nanometers, while ultrafine particles, on the other hand, are

sized between and nanometers. Similarly to ultrafine particles, nanoparticles are sized between and

nanometers, though the size limitation can be restricted to two dimensions. Nanoparticles may or

may not exhibit sizerelated properties that differ significantly from those observed in fine particles or

bulk materials , . Nanoclusters have at least one dimension between and nanometers and a narrow

size distribution. Nanopowders are agglomerates of ultrafine particles, nanoparticles, or

nanoclusters. see more..