Carbon's new champion: Theorists calculate atom-thick carbyne chains may be strongest material ever

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.