FTIR STUDY OF ULTRADISPERSED DIAMOND POWDER SYNTHESIZED BY EXPLOSIVE DETONATION

Ultradispersed diamond (UDD) powders synthesized by explosive detonati on were studied by FTIR to explore their surface functional groups. De convolution and second derivative spectra and curve fitting techniques were used to ascertain the frequencies of functional groups. Samples after oxidation by two kinds of mixed acid and after reduction in hydr ogen were investigated. Experimental results indicated that several ty pes of carbonyl groups are predominant on the surface of UDD, the cont ents of which are related to the methods of acid treatment. The main r eactions of hydrogen treatment are the conversion of carbonyl groups t o hydroxyls, and further to C-H bonding. After reoxidation of the hydr ogen treated samples, the spectra recovered to their original levels, which indicated that reduction reactions of the surface functional gro ups are reversible.