Nanopowder

A certain content of the nanoscale fraction can be found in many submicron powders, but, as a rule, this amount is insignificant. The presence of such a nanodispersed fraction does not give grounds to consider the entire powder as "nanopowder." Separate cases of nanopowders are possible when submicron conglomerates consist of bound nanoscale crystallites and / or blocks, but with a certain physical effect (ultrasonic dispersion , mechanical activation, etc.) they can decay into nanoparticles.

Nanopowders are characterized by:

• average particle size and particle size distribution;
• average crystallite size and crystallite size distribution;
• the degree of particle agglomeration (weak agglomeration — particle bonding due to van der Waals interactions; strong aggregation is characterized by strong interparticle bonds);
• specific surface area;
• chemical composition of the volume of particles;
• the composition of the cross section for particles of the core-shell;
• particle morphology;
• chemical composition of the surface;
• crystal structure of nanoparticles;
• moisture content and other adsorbates;
• flowability (fluidity);
• bulk density;
• color.

Commercial nanopowders ( English bulk nanoparticles ) - nanopowders produced on an industrial scale by established industrial technologies. Volumes of production of commercial nanopowders vary depending on the nature of application and market requirements. For example, for carbon black , titanium oxide and silicon oxide, the volumes are hundreds of tons, for nanophosphors - hundreds of kilograms, for nanopowders used in medicine - kilograms. ^[one]

• Nanopowder Compaction
• Nanopowder particle
• Pyrolytic production of nanopowders
• Plasma-chemical synthesis of nanopowders
• High energy mechanical grinding
• Ultrafine system

• NanoDictionary // Nanotechnology Perceptions. 2005. No1. P. 147-160.