Nanotubes, cylinders of carbon atoms with diameters ranging from less than 1 nm to 300 nm, are some of the strongest, stiffest materials known. Furthermore, these materials are either conductors or semiconductors, depending on their structure and environment, and have some physical properties that have no counterpart in macroscopic materials. Indeed, there has been enormous interest in the commercialization of nanotubes for both near and distant applications, and several of these applications will be successful shortly. However, many articles have presented wildly misleading information concerning these materials'' manufacture, markets, and applications.
According to an updated report from Business Communications Company, Inc, RGB-245R Nanotubes: Directions and Technologies, estimates of the total volume of research based on nanotubes (both single wall and specialty multiwall nanotubes) that have been produced worldwide to date, range from 10-20 kg, with a value of approximately $5-$10 million. This report estimates that 22.1 kg of research grade nanotubes have been produced through 2002, with a value of $11.9 million.
The current accepted wisdom is that nanotubes are produced in very small quantities and cost more per gram than gold. While there is certainly some truth to this conventional wisdom, the actual situation is somewhat more complex. The carbon nanotube market is divided into two separate industries. There is the industry devoted to research materials, and like other research materials, carbon nanotubes are produced in small volumes at high cost.
There is also a second, already well established nanotube industry: multiwall nanotubes have been used to modify polymers for over 5 years, and these modified polymers are already sold in million pound plus quantities. These modified polymers are conductive and have been used in ESD applications in several industries, including the disk drive/computer industry as well as the automotive industry. It is also possible to use these polymers in electrostatic paint applications; the automotive industry has been producing exterior parts, such as mirror housings, with these polymers.
Overall, these industries are quite separate at this point in time, and have little in common other than the fact that they produce nanotubes. The pricing differential between research nanotubes and bulk nanotubes used in polymer modification is between 3 and 4 orders of magnitude, which means that there is really little overlap. Consequently, this report does not sum up these industries, since they are too disparate.
While nanotubes will be used in research for decades to come, the research market for materials is always smaller than that of commercial applications. Possible commercial applications of nanotubes have been quite wide-ranging and include composites, electronics, actuators, displays, microscope probe tips, batteries, capacitors, and fuel cells. Some of these applications are quite fanciful and might never reach fruition, whereas other applications might reach commercialization within the next five years.
Although the high cost of nanotubes has been often cited as a barrier to commercialization for nanotube applications, it is something of a red herring. High cost is more a function of limited production, unproven processes, and the technical stumbling blocks that plague nearly all new materials; should production of nanotubes increase, then cost reductions would quickly follow.
The value of long-term applications of nanotubes can easily exceed several billion dollars, but precisely when these applications will become available is debatable. While nanotubes have been touted as a replacement for silicon in transistors in integrated circuits, it is highly unlikely that nanotubes will be used for this purpose within the next five years. If and when nanotubes become viable candidates to replace silicon in this application, then clearly the value of these applications will be great indeed. Larger-scale applications of nanotubes include fuel cells, but this market is also not that close to large-scale commercial development.
In contrast to these long-term applications of nanotubes, applications that have already had some limited commercial success include probe tips for atomic force microscopes and cold cathodes in X-ray devices. Nanotubes might be widely used in military, consumer, and industrial products in less than five years'' time.