Despite the sharp interest to nanodiamonds and rapid development of this industrial branch, Russian scientists still remain trendsetters in growing tiny diamonds, but it is getting harder every day. St. Petersburg recently hosted a remarkable event - International symposium "Detonation Nanodiamonds. Technology. Properties. Applications".

Scientists started industrial synthesis of diamonds in midfifties of the twentieth century. This synthesis was performed by means of graphite transformations in chambers, which provided very high presuure - tens of thousands of atmospheres - and very high temperatures - about 1500 degrees Centigrade. Each year world synthesis of such artificial diamonds produces hundreds thousands carats of these gems, which size from single microns to hundreds of microns - scientists call them diamond micropowders.

Today innovation technologies tend to shift from micro- to nanosizes, that is why industry needs diamonds of appropriate size. First nanodiamonds were synthesized in the Soviet Union, and commercial production of these carbon treasures weas launched in late eighties of the twentieth century. As a starting material chemists chose carbon of explosive substances, thus high presure and temperature, necessary for forming diamond structure from atoms of carbon, were generated during an explosion. The shorter an explosion was, the smaller diamond crystals appeared, sometimes they were as small as one billionth part of meter.

For a long time no scientific works of explosive synthesis appeared in open records due to that topic being top secret. This is possibly the reason why described technology of nanodiamond synthesis from carbon of explosives was invented in Soviet Union several times by different independent teams of inventors. Later, in 1988, these papers were published in Russia and the United States and were widely citated. Since that times inventors have come a long way. Scientists have found out that detonaion nanodiamonds showed some unusual properties. Latest research revealed that nanodiamonds could be a great basis for nanocompositional materials, coatings with unique mechanical properties, elements for nanoelectronics, selective sorbing agents and catalysts and objects for medical and biological applications. Nanodiamonds significantly improve quality of microabrasive and polishing materials, lubricating oils, various rubbers, magnetic recording systems and allow growing diamond films on various carrier materials.

Every schoolchild knows that diamond and graphite consist from carbon atoms, and their properties, being so different form each other, depend only on mutual disposition of atoms in their crystal lattice. Nanosize diamonds, when heated under some certain conditions, change their structure and form nested carbon spheres - nanomatreshka or carbon bulb. This bulb can again form a nanodiamond (a structure with diamond lattice) - after being treated by electronic beam. Well, a hollow carbon nanosphere is nothing but a recently disovered and very popular now fullerene molecule.

Scientists love the opportunity to study structural transformations of nanosize objects, but the discovery of nanodiamonds in meteorites is also very intriguing. Nanodiamonds offer great prospects for our industry.

Source: Science & Life

Kizilova Anna