One of the editors at Nature has written a good (free) article that provides some of important perspective about the movement of nano-carbon products (fullerenes, carbon nanotubes and, more recently, graphene) from lab to sustainable markets.
Richard Van Noorden, with quotes from a number or researchers and business reps, describes what a tricky path it can be to go from super-promising materials to specific applications to efficiency-scaled production capacity.
He notes that the first of these to emerge, fullerene, has been pretty much a commercial flop. CNTs emerged in the early 1990s and their semiconducting and metallic-type properties, not to mention their ruggedness, has teased R&D groups and investors ever since. But, CNTs electrical properties can be difficult to control and manufacturing pure bulk CNTs in predictable dimensions and orientations has been illusive. The same same problems are being faced with the newer graphene.
The problem with electronics is that a decent and cheaper alternative is readily available: silicon chips. Van Noorden quotes one organic chemist who points out that, “There have been millions and person-years and trillions of dollars put into the development of silicon electronics. Asking graphene to compte with silicon now is like asking a 10-year-old to be a concert pianist because we’ve been giving him piano lessons for the last six years.”
Van Noorden provides an overview of some of the pros and cons of CNTs and graphene in various applications and how the cost-benefit model can shift over time (e.g., graphene looks more promising in touch-screen applications as the cost of indium – and thus ITO – trends upwards .)
But even in less esoteric applications, such as using CWTs and graphene flakes in composites, these materials that can retail in the hundreds of dollars/kg are competing with substitutes that sell for less than a dollar/kg. Even with an expected stream of science and manufacturing innovations, experts like Lux Research estimate the $/kg for CNTs will only drop by half in the next ten years.
That’s not a blazing speed for price reduction, but one of the experts Van Noorden interviews points out, the arc of now-ubiquitous carbon fiber began very slowly, eventually found usage in less cost-conscious military applications and much later made its way into large-scale commercial usage.
Nevertheless, manufacturers are bringing more and more capacity on line, and as they do so, they will be scrambling for outlets. Some early niches for graphene will emerge like they have for CWTs (Van Noorden speculates that supercapacitors, such as the one I recently wrote about, electrodes and flexible electronics may pay off), but despite the excitement everyone will have to be patient — perhaps very patient — until they see the first truly transformational uses.