Key words: supercritical fluid, diamond blend, ultradisperse diamond
In this paper, a safe method for processing of the diamond blend using supercritical
isopropanol is proposed, and the efficiency of the method is shown.
With the help of a specially designed unit, several samples of diamond blend powder
were processed. Raman spectra, as well as infrared spectra of the samples were obtained
before and after processing, a comparative analysis of the spectra was made. In addition,
an X-ray study of the samples was carried out. It is shown that after treatment of
supercritical fluid, a noticeable decrease in the IR absorption intensity of the bands of
oxygen-containing bonds is observed, which indicates an effective etching of the
diamond crystallite shell during processing. Also a noticeable increase in the half-width
of the diamond line is observed in the Raman spectra of samples subjected to processing.
We explain this by the reduction in the dimensions of diamond nanocrystallites due to
etching of the surface defect layer. Thus, we can talk about the prospects of using the
proposed method for cleaning of diamond blend, which is widely used in many
industries now (in particular, in biology, chemistry, medicine). It should also be noted
that this method has significant advantages over traditional cleaning methods, which
usually involve the use of aggressive hot acid media for long periods of time.
doi:10.1134/S1990793119070121