Detonation nanodiamonds simultaneously purified and modified by gas treatment

The gas phase method of simultaneous purification and modification of detonation nanodiamond has been developed that allows producing nanodiamonds of the superior quality and with high stability of suspensions. The technology uses a fluidized bed reactor fed with an air enriched with oxygen or ozone. In the reactor, the non-diamond byproducts of detonation synthesis, mostly graphite, are reacted to ozone at the elevated temperature and converted to CO2 or CO. Simultaneously the surface of detonation nanodiamonds is depleted of non-diamond carbonaceous byproducts of the detonation synthesis and enriched with oxygen-containing chemical groups. The technology is an attractive alternative to a commonly used method of detonation soot treatment with concentrated acids or other strong liquid oxidizers. In this paper, we report on the reactor, method and physical chemical properties of nanodiamonds processed from soot by treatment in air enriched with ozone. The technology is environmentally friendly and may find wide application in industry. (C) 2007 Elsevier B.V. All rights reserved.