Deep purification of detonation nanodiamond material

The paper presents new alternative procedures of chemical purification of detonation nanodiamonds and diamond-bearing detonation soot to remove water-insoluble metal-containing impurities through a high-temperature treatment using solutions of complexons of concentration 0.5 to 20 wt %, where the ratio between the detonation nanodiamond material and the complexon is above 0.2. The following substances can be used as complexons: sodium 2,3-dimercaptopropanesulfonate, disodium dihydrogen ethylenediaminetetraacetate (Trilon), thiocarbamide, potassium rhodanate, dicyandiamide, hexamethylenetetramine. Purification of detonation nanodiamonds can be also performed by exposing them to an ultrasonic action. A combination of the ultrasonic treatment and treatment with complexon solutions has proved most efficient, significantly reducing the amount of metal-containing impurities.