Disaggregation of aggregated nanodiamond clusters

1. A method of disaggregating nanodiamond clusters comprising:

milling aggregated nanodiamond clusters with a plurality of milling bodies and a solid disaggregating agent having a Mohs hardness less than 6 Mohs hardness units, the aggregated nanodiamond clusters comprising nanodiamonds and having an initial mean effective diameter, the milling being done for a time sufficient to produce a nanodiamond particulate form having a mean effective diameter less than the initial mean effective diameter of the aggregated nanodiamond clusters.

2. The method of claim 1 wherein the aggregated nanodiamond clusters are aggregated nanodiamond clusters resulting from a detonation process.

3. The method of claim 1 wherein the milling bodies have a Mohs hardness less than 10.

4. The method of claim 1 wherein the milling bodies comprise ceramic, glass, polymer, or metal.

5. The method of claim 1 wherein said solid disaggregating agent is present as a slurry.

6. The method of claim 1 wherein the milling is done in the presence of a liquid.

7. The method of claim 1 wherein the disaggregating agent is present in an amount sufficient to prevent measurable attrition damage to the milling bodies and/or measurable contamination of the nanodiamond particulate form with said attrition damage.

8. The method of claim 1 wherein the ratio of nanodiamond clusters to disaggregating agent is in the range of 1:1 to 1:50 by weight.

9. The method of claim 1 wherein the disaggregating agent is generally recognized as safe (GRAS) by the pharmaceutical industry.

10. The method of claim 1 wherein the disaggregating agent is a crystalline inorganic salt.

11. The method of claim 10 wherein the crystalline inorganic salt is a crystalline alkali metal or alkaline earth metal halide salt.

12. The method of claim 11 wherein the crystalline inorganic salt is a chloride salt.

13. The method of claim 12 wherein the chloride salt is sodium chloride.

14. The method of claim 1 wherein the disaggregating agent is a crystalline sugar, organic acid, or organic salt.

15. The method of claim 14 wherein the disaggregating agent is a crystalline lactose, maltose, sucrose, succinic acid, fumaric acid, maleic acid, tartaric acid, citric acid, pharmaceutically acceptable salt thereof, or mixture thereof.

16. The method of claim 15 wherein the disaggregating agent is sucrose.

17. The method of claim 1 wherein the time is in the range of 5 minutes to 600 minutes.

18. The method of claim 1 providing a portion of the nanodiamond particulate form having an effective diameter of less than 40 nm.

19. The method of claim 18 wherein the portion of the nanodiamond particulate form having effective diameters less than 40 nm is greater than 50 vol % of the total nanodiamond particulate form content as measured by light scattering techniques.

20. The method of claim 1 further comprising separating the nanodiamond particulate form from at least a portion of the disaggregating agent.

21. The method of claim 20 wherein the separating comprises dissolving at least a portion of the disaggregating agent in a solvent.

22. The method of claim 21 wherein the solvent is aqueous.

23. The method of claim 1 , further comprising dispersing the nanodiamond particulate form in a solvent.

24. The method of claim 23 wherein the solvent is aqueous.

25. The method of claim 24 further comprising adjusting the pH of the aqueous solvent to greater than 6.

26. The method of claim 25 wherein the pH is in the range of about 10.5 to about 11.5.

27. The method of claim 1 , wherein said solid disaggregating agent has a Mohs hardness less than 5 Mohs hardness units.

28. The method of claim 1 , wherein said solid disaggregating agent has a Mohs hardness less than 4 Mohs hardness units.

29. The method of claim 1 , wherein said solid disaggregating agent has a Mohs hardness less than 3 Mohs hardness units.

30. The method of claim 1 , wherein said solid disaggregating agent has a Mohs hardness less than 2.5 Mohs hardness units.