Deagglomeration of Detonation Nanodiamonds

It is well known that a commercial powder of detonation nanodiamonds (DND) and their aqueous suspensions consist of agglomerates of 4-5 nm crystalline diamond grains. We have submitted a method for production of stable mono-disperse hydrosol of 4 nm isolated DND particles. The method includes deep purification commercial DND from metal impurities and appropriate control of its residual amount by electronic spin resonance, annealing of purified DND in air and centrifugation. The main result of the study demonstrates that centrifuging of a DND hydrosol of particles with a high negative zeta potential produced by deep purification and air annealing results into breakup of the agglomerates. A model explained high strength of the DND agglomerates has been discussed.