Rice University researchers have determined from first-principle calculations that carbyne would be the strongest material yet discovered. The carbon-atom chains would be difficult to make but would be twice as strong as two-dimensional graphene sheets. (Image Credit: Vasilii Artyukhov/Rice University)
Carbyne will be the strongest of a new class of microscopic materials if and when anyone can make it in bulk.
If they do, they’ll find carbyne nanorods or nanoropes have a host of remarkable and useful properties, as described in a new paper by Rice University theoretical physicist Boris Yakobson and his group. The paper appears this week in the American Chemical Society journal ACS Nano.
Carbyne is a chain of carbon atoms held together by either double or alternating single and triple atomic bonds. That makes it a true one-dimensional material, unlike atom-thin sheets of graphene that have a top and a bottom or hollow nanotubes that have an inside and outside.
According to the portrait drawn from calculations by Yakobson and his group:
- Carbyne’s tensile strength – the ability to withstand stretching – surpasses “that of any other known material” and is double that of graphene. (Scientists had already calculated it would take an elephant on a pencil to break through a sheet of graphene.)
- It has twice the tensile stiffness of graphene and carbon nanotubes and nearly three times that of diamond.
- Stretching carbyne as little as 10 percent alters its electronic band gap significantly.
- If outfitted with molecular handles at the ends, it can also be twisted to alter its band gap. With a 90-degree end-to-end rotation, it becomes a magnetic semiconductor.
- Carbyne chains can take on side molecules that may make the chains suitable for energy storage.
- The material is stable at room temperature, largely resisting crosslinks with nearby chains.
That’s a remarkable set of qualities for a simple string of carbon atoms, Yakobson said.