Laser blasts make tiny diamonds out of plain old plastic. Yes, the kind used in soda bottles.
When extruded to about a million times Earth’s atmospheric pressure and heated to thousands of degrees Celsius, polyethylene terephthalate, or PET, forming nanodiamondsphysicist Dominik Kraus and colleagues report on Sept. 2 in scientific progress.
Ice giants like Neptune and Uranus have similar temperature, pressure and chemical element combinations to the materials in the study, suggesting that diamonds may be falling in the interiors of these planets. What’s more, the researchers say, the new technique could be used to make nanodiamonds for quantum devices and other applications.
In the new study, the researchers trained a laser on plastic samples. Each laser blast sends a shock wave through the plastic, increasing the pressure and temperature inside. Probing the material with X-ray bursts revealed that nanodiamonds had formed.
Previous research has made diamonds by compressing compounds of hydrogen and carbon. But PET, commonly used in food and beverage packaging, contains not only hydrogen and carbon, but also oxygen. This makes it more suitable for the composition of ice giants like Neptune and Uranus. Oxygen appears to contribute to the formation of diamonds, says Krauss of the University of Rostock in Germany. “Oxygen picks up hydrogen,” he said, leaving carbon that can form diamonds.
Nanodiamonds are usually produced with explosives, a process that is not easy to control, Krauss said.New technology could make nanodiamonds that are easier to tailor for specific uses, such as Quantum devices made using defective diamond For example, where nitrogen atoms replace some carbon atoms (SN: July 6, 2018).
“It’s a cool idea. You take water bottle plastic; you laser cut it to make diamonds. I don’t know how practical it is,” said Marius Millot, a physicist at Lawrence Livermore National Laboratory in California who was not involved in the research. a new study. How easy it will be to recover the diamonds is unclear, he said. But, “it’s pretty neat to think about this idea.”