Nanodiamond refers to the diamond with grain size of 1~100nm. Nanodiamond particles were first produced by detonation in the USSR in the 1960s, but they remained essentially unknown to the rest of the world until the end of the 1980s. Nanodiamond inherits most of the superior properties of bulk diamond and delivers them at the nanoscale. These properties include superior hardness and Young’s modulus, low friction coefficient, low surface roughness, large specific surface area, biocompatibility, optical properties and fluorescence, high thermal conductivity and electrical resistivity, chemical stability, and the resistance of nanodiamond to harsh environments.

Synthesis

Nanodimaond powder can be synthesized by the methods of detonation technique, laser ablation, high-energy ball milling of high-pressure high-temperature (HPHT) diamond microcrystals, plasma assisted chemical vapour deposition (CVD), autoclave synthesis from supercritical fluids, chlorination of carbides, ion irradiation of graphite, electron irradiation of carbon ‘onions’and ultrasound cavitation, with the first three of these methods being used commercially.

Application

Due to the unique properties of nanodiamond, nanodiamond have been used for precision polishing and lubrication, electrolytic and electroless metal plating, catalysis, composite coatings, high-performance metal matrix composites for many years. More recently, they also have been used in other applications such as the aerospace, chemical analysis and biomedicine fields.