Nanoparticles

Nanomaterials are molecules with their size lying basically in nano range that are usually synthesized by proper arrangement of nanoparticles. These particles are basically solid phase materials with average size range 1 to 100 nm. They have gained prominent importance in technological development because of their biological and physiochemical properties. They are usually classified or characterized on the basis of size, shape, origin, and composition. The chapter reviews nanoparticles, their detailed classification, and commercialized products from nanoparticles. Because of enhanced production of nanomaterials and their increased applications in biological and industrial fields, the issues related to toxicity or contamination are inevitable. The differences between engineered nanoparticles and natural nanoparticles have been described along with their sources.