UNITED STATES (OBSERVATORY NEWS) — The manufacture of artificial diamonds is an expensive process that requires huge energy costs. But now chemists have in their arsenal the technology of creating much cheaper gems from oil waste. For this, the temperature of the gas burner is sufficient (however, there is one “but”, which we will discuss below).
The achievement is described in a scientific article published in the journal Science Advances.
Mankind has been making artificial diamonds for over 60 years. This incredibly hard, transparent and chemically resistant material is indispensable in many fields, from ordinary glass cutting to quantum technology .
But even synthetic diamond is expensive. To reproduce the conditions for the formation of this mineral in the depths of the Earth, huge temperatures and pressures are required. If you use a catalyst, the process is somewhat simplified, but the quality of the final product is deteriorated.
Now chemists from the USA and China have developed a new technology for producing precious material. It does not require catalysts and works in far less exotic conditions than classic recipes.
The starting material is diamondoids. These are hydrocarbons with a special molecular structure. In the spatial arrangement of carbon atoms, such a molecule is similar to one, two, or three cells of the diamond crystal lattice.
Diamondoids were discovered back in the 1930s. To get them, it’s not even necessary to process crude oil: you can use the natural coating on the walls of tankers. It is a white and slightly sticky odorless mass that does not resemble a jewel in any way. This is the source material that the research team chose.
Chemists laid out a small amount of substance that can be moved with a standard needle on a diamond anvil. Here is another illustration of the usefulness of this mineral: even for the manufacture of diamond, scientists needed a diamond! Let us explain that such anvils help to create a lot of pressure, and their transparency makes it possible to heat the sample with a laser beam.
Initially focusing on reducing the pressure needed to produce diamonds, scientists turned the source material into diamond at 120 thousand atmospheres and a temperature of 1700 degrees Celsius. Having set the goal of minimizing the temperature, they got a gem at only 600 degrees Celsius (this is less than the flame temperature of a household gas stove). But the pressure they needed to increase to 200 thousand atmospheres.
These conditions look extreme, but they are much milder than those that are usually used for the synthesis of diamonds.
Through computer simulation, the researchers found that the diamondoid turns into diamond immediately, without an intermediate stage of graphite. Most quickly, the precious material is formed from triamantane, the molecule of which is similar to the three cells of the diamond crystal lattice. It takes literally fractions of a second to transform. Hydrogen, which is part of the diamondoid, is volatilized.
Of course, in its current form, technology allows you to get only very small diamonds: after all, their size is limited by the area of the diamond anvils. Now, the challenge for researchers is to learn how to make diamonds from diamondoids on an industrial scale.
This article is written and prepared by our foreign editors writing for OBSERVATORY NEWS from different countries around the world – material edited and published by OBSERVATORY staff in our newsroom.
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