Is Graphene ending the promises for Carbon Nanotubes?
Let me start with what’s in the background, and why I think this is a valid and potentially a highly influential technological issue these days. This month it rather surprisingly hit the news that three years after Bayer MaterialScience (a leader in material solutions) invested 22 million euros into a carbon nanotube (CNT) production facility which had a very promising future, then they decided to close it down because of lacking groundbreaking applications in sight.1 In other words they trusted, somewhat blindly, that the growth rate of worldwide CNT demand could increase up to the level of the production capacity. Well, as you’d guess this is still very much unbalanced toward the latter. Or, is it the success of the Nobel Prize-winning big brother - graphene - that is shaking the whole CNT empire?
When Sumio Iijima discovered nanotubes in 1991 the future looked particularly bright for this novel carbon allotrope, holding potential applications in several industrial sectors, such as coatings, electronics, composites and energy storage. Yet more than 20 years after that famous Nature paper2 it is only the application as a reinforcing material in plastics and composites that was somewhat able to meet the expectation. 2013 started with dozens of companies producing several thousands of metric tons of multiwall nanotubes a year, but only one month in the new year the production decreased by around 10% as a result of Bayer MaterialScience leaving the business. The circle of the remaining big players still includes companies such as the Japanese Showa Denko K.K. (recently partnered up with Mitsubishi, and mainly producing vapor grown carbon fiber VGCFTM), Nanocyl (spun off from the University of Namur in early 2000s) and the US-based CNano Technology Ltd., Arkema Inc. and Hyperion Catalysis, all with annual capacities of several hundreds of metric tons.
In contrast to CNTs, graphene in the past few years has been developing at an astonishingly high rate, both in the area of applications and production. It is often called as the next disruptive technology representing unique and highly attractive electrical, optical and mechanical properties.3 Although it is very similar to carbon nanotubes (essentially a single wall nanotube is a rolled up graphene sheet), it is much easier to make. So there is one advantage already, and the industry is currently facing an annual production capacity of 1,000s of metric tons in China alone. Targeting the same sectors as CNTs, but developing at a much faster rate would easily mean that graphene is going to take over the market from nanotubes and/or create its own market. Maybe this was the issue that has been realized by the management of Bayer MaterialScience, and has led to the decision of leaving a market currently estimated to worth around 600-700 million dollars. We don’t know yet, but that is very likely to be the case.
It is a bit too early to predict the outcome of this battle, but in my opinion other leading companies might as well follow the example setup by Bayer MaterialScience, and in turn the applications of CNTs could fairly easily shrink down to the currently existing composites, or, in time even vanish completely. This won’t be just caused by a global meltdown that has set back the worldwide demand for carbon nanotubes considerably during the years 2008 and 2009, rather an evolutionary thing that allows similar technologies to jump across one another.
References: 1 http://news.bayer.de/baynews/baynews.nsf/id/Bayer-MaterialScience-brings-nano-projects-to-a-close 2 Iijima, Sumio (1991). "Helical microtubules of graphitic carbon". Nature 354 (6348): 56–58 3 https://revamp.chemaxon.com/blog/graphene-the-next-disruptive-innovation/