The effect of the methods of recovering diamond nanopowders on their physicochemical properties

The effect has been considered of the methods of recovering (liquid oxidation of nondiamond carbon with a mixture of sulphuric and chromic acids, selective gas oxidation of nondiamond carbon in the presence of copper salts as a catalyst, and oxidation of nondiamond carbon with a mixture of concentrated sulfuric and nitric acids) diamond nanopowders from detonation-synthesized diamond-carbon products on physicochemical properties of diamond, for which the structural state of the diamond surface is responsible. It has been found that diamond nanopowders recovered using different technologies exhibit a decrease of the volume fraction of aggregates among particles. Nanodiamonds recovered by a catalytic gas-phase oxidation in the presence of copper have been found to be characterized by the highest adsorption activity, thermostability, and electroconductivity due to the carbon-containing cover of a complex composition. The recommendations have been given on the use of diamond nanopowders recovered by different technologies.