Acta Phys. -Chim. Sin. ›› 2003, Vol. 19 ›› Issue (11): 993-995.doi: 10.3866/PKU.WHXB20031101

• Communication •     Next Articles

A New Method for Deaggregation of Nanodiamond from Explosive Detonation—— Graphitization-Oxidation Method

Xu Kang;Xue Qun-Ji   

  1. State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000
  • Received:2003-07-21 Revised:2003-09-06 Published:2003-11-15
  • Contact: Xu Kang E-mail:kangxu@lsl.ac.cn

Abstract: Nanodiamond (ND) prepared by explosive detonation has primary particles of 4~6 nm in diameter, but it undergoes severe aggregation in forming aggregates of hundreds of nm,even several μm in diameter. A new method for the deaggregation of nanodiamond (ND) is developed and some preliminary results using this method are presented: ND is first graphitized in nitrogen at 1 000 ℃ during which thin graphite layers are formed on the surface of the diamond particles and at the particle boundaries. The sample is then oxidized by air at 450 ℃ to remove the formed graphite layers. After such treatment the sample is suspended in water by ultrasonics, and the particle size distributions were measured by the laser scattering method. It has been found that the diameter of about 50%(w) of the ND particles can be reduced to less than 50 nm, while such ultrafine particles are absent in the suspension of the untreated ND. It is suggested that the deaggregation is caused by the removal of the graphite layers formed at the particle boundaries in the stage of oxidation. It is also found that after oxidation, some aggregates with larger diameters (1 000~2 000 nm) are formed, which can be explained by the formation of inter-particle ethereal bondings (C-O-C) during the oxidation by air.

Key words: Nanodiamond(ND), Deaggregation, Graphitization, Oxidation