A few decades ago, we knew of only a few forms of carbon: diamond, graphite, and amorphous carbon. Today, thanks to rapid scientific advancements in the world of nanotechnology, we have discovered many other forms of carbon.
One of the most important developments is the carbon nanotube (CNT), which is related to graphite. The molecular structure of graphite resembles stacked, one-atom-thick sheets of chicken wire. In conventional graphite, the sheets of carbon are stacked on top of one another, allowing them to easily slide over each other. When these sheets are rolled into a cylinder and their edges joined, they form CNTs, which offer extraordinary mechanical, electrical, thermal, optical, and chemical properties.
As a carbon-based product, CNTs have almost none of the environmental or physical degradation issues common to metals, such as thermal expansion and contraction, corrosion, and sensitivity to radiation. CNTs come in a variety of diameters, lengths, and functional group content, and are available for industrial applications in bulk quantities of metric ton quantities.
In light of their unique properties, CNTs are one of the most sought-after materials today and are used in dozens of applications, including aerospace, electronics, medicine, defense, automotive, energy, construction, and even sports. Scientists are developing new products with CNTs at a staggering pace – as textiles, petrochemicals, plastics, paints and adhesives, medical devices, ceramics, batteries, health products, and solar panels, to name a few.
The aerospace and military sectors saw the potential of CNTs early on as ways to leverage electrical and thermal properties and to strengthen and lighten protective armor. Increased performance at lighter weight saves fuel and enables increased payload. Unlike the metals that its products replace, the carbon structures are not compromised by corrosion, radiation and fatigue.
As an example of early adoption by the aerospace industry, NASA incorporated a unique nanotube-based sheet material developed by a New England based company into the Juno spacecraft, which launched on August 5, 2011, to provide protection against electrostatic discharge (ESD) as the spacecraft made its way through space to Jupiter. The nanotube-based material was used as a surface layer on several critical components of the flight system’s altitude control motor struts and the main engine housing.
CNTs can also be used as the electrodes in batteries and capacitors to provide more current and better electrical and mechanical stability than other materials. Engineers are looking at CNTs as a possible cooling solution that could help accelerate the processing speeds of computer chips used in next-generation smartphones and supercomputers. In a consumer-based application, sports manufacturers use CNTs in a variety of equipment such as tennis and badminton rackets and bicycle frames.
The applications for CNTs seem limitless. From inside a computer chip to outer space, CNTs are proving that significant benefits can come from the smallest of technologies.