The sixth element, carbon, has given us an amazing abundance of extraordinary materials. Once there was simply carbon, graphite and diamond. But in recent years chemists have added buckyballs, nanotubes and any number of exotic shapes created out of graphene, the molecular equivalent of chickenwire.
So it’s hard to believe that carbon has any more surprises up its sleeve. And yet today, Mingjie Liu and pals at Rice University in Houston calculate the properties of another form of carbon that is stronger, stiffer and more exotic than anything chemists have seen before.
The new material is called carbyne. It is a chain of carbon atoms that are linked either by alternate triple and single bonds or by consecutive double bonds.
For a start, they say that carbyne is about twice as stiff as the stiffest known materials today. Carbon nanotubes and grapheme, for example, have a stiffness of 4.5 x 10^8 N.m/kg but carbyne tops them with a stiffness of around 10^9 N.m/kg.
Just as impressive is the new material’s strength. Liu and co calculate that it takes around 10 nanoNewtons to break a single strand of carbyne. “This force translates into a specific strength of 6.0–7.5×10^7 N∙m/kg, again significantly outperforming every known material including graphene (4.7–5.5×10^7 N∙m/ kg), carbon nanotubes (4.3–5.0×10^7 N∙m/ kg), and diamond (2.5–6.5×10”7 N∙m/kg4),” they say.
So, can we create a beanstalk yet?