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Diamond Nanothread’s Flaws Can Make it the Next Supermaterial

Diamond nanothreads “may become as ubiquitous a plastic in the future, used in everything from clothing to cars,” according to a researcher who thinks they can outperform brittle carbon nanotubes.

Carbon nanotubes are hollow cylindrical tubes 10,000 times smaller than human hair. They may be stronger than steel but they are also brittle. Dr Haifei Zhan of Queensland University of Technology says that diamond nanothreads (DNT) are “even thinner, incorporating kinks of hydrogen in the carbon’s hollow structure”. He says that these Stone-Wales (SW) defects reduce brittleness and add flexibility, making DNT “a great candidate for a range of uses”.

DNT’s name refers to the way the carbon atoms are packed together like diamond, giving it phenomenal strength. “While both carbon nanotubes and DNT have great potential, the more I model DNT properties, the more it looks to be a superior material,” Zhan said.

“The SW defects give DNT a flexibility that rigid carbon nanotubes can’t replicate. Think of it as the difference between sewing with uncooked spaghetti and cooked spaghetti.

“My simulations have shown that the SW defects act like hinges, connecting straight sections of DNT. And by changing the spacing of those defects, we can a change – or tune – the flexibility of the DNT.”

The research, published in Nanoscale, adds to other results from Zhan’s DNT modelling. For example, he has found that SW defects create irregular surfaces on the DNT, allowing it to bond well with polymers. DNT could therefore be used to reinforce nanocomposite materials. “I am excited about the potential range of applications it could be used for, given we’ve proven we can control its flexibility, conductivity and strength,” Zhang said.

“Carbon is the most abundant element on the planet. It’s a renewable resource, so the cost of the raw material is extremely low. Once the manufacturing costs are viable, DNT would likely be used primarily in mechanical applications, combined with other materials to make ultrastrong, lightweight composites and components such as plane fuselages.

“I plan to test how DNT performs as a two-dimensional networked structure – a sheet or layer – for potential use in flexible electronics and screens. I also want to test its viability as a fibre for textiles or rope, from bullet-proof vests and hard-wearing work gear to a replacement for steel cables in bridge construction.

“There’s already talk in the global carbon community of DNT being the best candidate yet for building a space elevator.”