In Troitsk, an industrial method was developed for producing ultrahard fullerite, a material harder than diamond.
The harder the cutting tool, the longer it will last and the better the workpiece can be processed. Physicists, chemists, technologists have created a lot of superhard materials, but, despite all efforts, for a long time natural diamond remained the hardest. The situation began to change with the discovery of new forms of carbon. Twenty years ago, as a result of long-term joint Russian-French research (see "Science and Life" No. 10, 1995) at the Institute for High Pressure Physics of the Russian Academy of Sciences. LF Vereshchagin was the first to synthesize ultrahard fullerite, which turned out to be harder than natural diamond, hence it got the name "ultrahard".
Fullerites are molecular crystals formed by C60 fullerene molecules. The first fullerites were obtained in 1990 at the Institute of Nuclear Physics in Heidelberg (Germany). The announcement of this discovery caused a flurry of work on the study of the properties and methods of synthesis of the new substance. Under the influence of high pressure and temperature, researchers obtained a variety of previously unknown phases formed by fullerene molecules. Among them were superhard fullerites. Ultrahard fullerite - the one harder than diamond - turned out to be a three-dimensional polymer composed of fullerite crystals.
Ultrahard fullerite remains the hardest material today: its hardness index ranges from 150-300 GPa (gigapascals) versus 70-150 GPa for natural diamonds. From a practical point of view, it is interesting not only for specialists in the processing of metals and other materials, but also for scientific research, primarily for measuring the hardness of superhard materials and the same diamond. A new method for measuring hardness using ultrahard fullerite was created at the Institute of Spectroscopy of the Russian Academy of Sciences back in 1997. Nevertheless, ultrahard fullerites have not yet received widespread use, since there are no ways to synthesize them on an industrial scale. This is due to technological difficulties: for the synthesis of ultrahard fullerite, a very high pressure is required - at least 13 GPa, or almost 130 thousand atmospheres. Modern technology does not allow to create it in a large-scale plant (industrial scale).
Researchers from the Technological Institute of Superhard and New Carbon Materials (Troitsk, Moscow Region), from MIPT, MISiS and Moscow State University. MV Lomonosov Moscow State University were able to bypass this limitation. They added CS2 to the starting reagents, which, as experiments showed, acts as a catalyst for the reaction of three-dimensional polymerization of C60. In the presence of carbon disulfide, the formation of a superhard material becomes possible at a lower pressure - 8 GPa, and the process proceeds at room temperature, while the synthesis of this fullerite in the absence of a catalyst requires heating to 1100 K (about 830 ° C). Carbon disulfide is relatively inexpensive and available: it is produced on an industrial scale, used in various industries, including chemical and textile industries, so the technology for working with it is well developed.