Carbyne, the world’s strongest known material, has always been elusive! For something so strong, it is very unstable, and its high reactivity has made it a challenge to create and isolate.
Scientists at the University of Vienna have now devised a method of mass producing carbyne. It can create stable chains 6,400 carbon atoms long, 64 times as long as the previous longest chain.
Carbyne is formally known as linear acetylenic carbon, a linear and infinitely long carbon chain. It is perfectly straight, due to its sp1 hybridisation, which means it can form alternating single and triple bonds to adjacent carbons. Considering hybridisation is a method of determining the way a molecule will bond. Carbyne’s sp1 hybridisation means that it can form two carbon–carbon sigma bonds, giving it its linear nature. The remaining two bonds are used to make up the triple bond by overlapping of the lone electron pairs to make pi bonds.
The scientists achieved production of this stable form of carbyne by creating it inside a double walled tube of rolled up graphene called a nanotube. This keeps it safe and straight, so that it can’t react with the air or itself. The ends were stabilised by adding end-capping groups. They confirmed their product using Raman spectroscopy, transmission electron microscopy and X-ray diffraction.
Carbyne is said to have a Young’s modulus of 32.7 TPa, that’s double that of graphene, and 40 times that of diamond! It also has electrical properties which vary with chain length, so as the length increases so does the conductivity. This makes it useful in the development of super-strong gadgets and devices, as well as even construction.
L. Shi, P. Rohringer, K. Suenaga, Y. Miimi, J. Kotakoski, J. C. Meyer, H. Peterlik, M. Wanko, S. Cahangirov, A. Rubio, Z. J. Lapin, L. Novotny, P. Ayala, T. Pichler , Nature Materials, 4th April 2016, Confirmed linear carbon chains as a route to bulk carbyne, http://www.nature.com/nmat/journal/vaop/ncurrent/full/nmat4617.html (accessed 23/04/2016)
Cheyenne Macdonald, Daily Mail, 14th April 2016, World’s strongest material: scientists create ‘wonder substance’ carbyne in large amounts for the first time, http://www.dailymail.co.uk/sciencetech/article-3538808/World-s-strongest-material-Scientists-create-wonder-substance-carbyne-large-amounts-time.html (accessed 23/04/2016)
Kathleen Riley, Science Alert, 12th April 2016, Scientists just got the first direct proof of stable carbyne – the world’s strongest material, http://www.sciencealert.com/scientists-have-discovered-a-way-to-mass-produce-the-world-s-strongest-material (accessed 23/04/2016)
James Billington, IBTimes, 14th April 2016, Carbyne: Scientists create ’holy grail’ strongest material in the world that’s tougher than graphene, http://www.ibtimes.co.uk/carbyne-scientists-create-holy-grail-strongest-material-world-thats-tougher-graphene-1554867 (accessed 23/04/2016)