Nanomaterials are also specialty
powders. The difference between a
nanoparticle and a
bog-standard speck of something is that the former has been specifically engineered for
particle size, proportion of
atoms in the grain boundaries or particle surfaces, and
morphology. Nanopowders usually range in size from 1 to 100
nanometers.
For example, nanoparticles of zinc oxide make for a better sunscreen, as they have uniform characteristics from particle to particle, enabling the properties of the sunscreen to be specifically tailored.
Tungsten-carbide and ceramic nanopowders are used in spray form to coat items to increase their surface hardness for scratch resistance, or to improve their slipperiness for liquid handling.
Graphite nanopowder is now used in ultracapacitors and batteries, since it provides a greater surface area for the chemical reaction than simple ground carbon.
Ceramic nanopowder can be used as a joining compound between two ceramic objects, creating a stronger bond when sintered than adhesives or ceramic slurry.
Nanopowders can also be used to imbue a material with properties not normally found. For example, there is work going on to saturate polymers with metallic or graphite particles to create conductive plastic.