METHOD OF MAKING DIAMOND-CARBON NANOPARTICLES Russian patent published in 2010 - IPC C01B31/02 C01B31/06 B82B3/00 

FIELD: chemistry.

SUBSTANCE: method involves thermal annealing nanodiamond powder in a sealed chamber in an inert atmosphere at temperature 1100-1700°C, continuous removal of gaseous desorption products and control of the parametre of the powder which characterises the ratio diamond/non-diamond carbon phase in the powder during annealing. The said parametre is determined from the amount of nitrogen released from the powder during annealing. Fractional content of the non-diamond carbon phase in the powder at any moment during annealing is calculated using the formula: θ=100(N/N₀), where θ is fractional content of the non-diamond carbon phase, %; N₀ is total amount of nitrogen in the nanodiamond powder; N is amount of nitrogen released during annealing. Gaseous desorption products during annealing are removed at a constant rate and partial pressure of nitrogen in the desorbed gases and amount of nitrogen N released during annealing is continuously measured. Total amount of nitrogen N₀ in the nanodiamond powder in the initial state is determined from the amount nitrogen released when annealing the powder at temperature 1600-1900°C until partial pressure of nitrogen reaches the background level in the chamber.

EFFECT: method enables to obtain bulbous nanostructures with a diamond nucleus, which enables to obtain material with given diamond/graphite content ratio and simplifies the process of controlling the diamond/graphite content ratio in the obtained powdered material.

3 cl, 2 tbl, 4 ex