Tuesday, August 04, 2009

US Patent 7569205 - Dispersion of nanodiamonds


Nanodiamonds have potential as additives to improve lubricants and for polishing. However, nanodiamonds can suffer from the same clumping problems of other nanomaterials. This patent teaches a processing method in which dimethyl sulfoxide is used to deaggregate the nanodiamonds. Claim 1 reads:

1. A method of processing detonation nanodiamonds to fractionate the detonation nanodiamonds comprising, in order:

providing detonation nanodiamonds,

forming a combination consisting essentially of said detonation nanodiamonds and a solvent, said nanodiamonds exhibiting a positive zeta potential in said solvent, said solvent consisting essentially of DMSO making up at least approximately 10% DMSO (v/v) in the solvent with any balance of the solvent consisting essentially of a polar solvent, wherein the DMSO increases or stabilizes the magnitude of the positive zeta potential of the detonation nanodiamonds in the combination,

applying a dispersive technique to said combination, subjecting said combination to a procedure that causes nanodiamond particles of a first size range to be substantially spatially separated from nanodiamonds of a second size range, and collecting said nanodiamonds of said first size range essentially free of said second size range.