Carbon nanotubes properties

The wide range of electronic, thermal, and structural properties of carbon nanotubes vary according to the different diameter, length, and direction of the nanotube ‘twist’. Many applications arise from their surprising properties, some of which are already being used in new and improved products. For example, carbon nanotubes are highly conductive both to electricity and heat - they exhibit an electrical conductivity as high as copper, and thermal conductivity as great as diamond.

Nanotubes can be either metallic or semiconducting, leading to the development of nanowires, nanoscale electrical components and nanoelectromechanical systems. They therefore offer amazing possibilities for creating future nanoelectronic devices, circuits and computers. Carbon nanotubes also have extraordinary mechanical properties - they are 100 times stronger than steel, while only one sixth of the weight. These mechanical properties offer huge possibilities - for example, in creating nanocomposites for a variety of application scenarios ranging from military and aerospace to medicine.

Applications

There are a lot of potential applications of carbon nanotubes including nanometer-sized semiconductor devices and interconnects; conductive and high-strength composites; devices for energy storage and energy conversion; sensors; field emission displays and radiation sources. Research is expected to lead to new materials, lubricants, coatings, catalysts, electro-optical devices, and medical applications.

Some applications already exist, others are under development. For example, tennis racquets containing carbon nanotubes are on the market. The nanotubes are used to reinforce the frame and improve the racquet's ability to absorb shocks. Reinforced tennis racquets are only one of many potential applications. Some Carbon nanotubes can be mixed with many different materials such as plastics and textiles for lightweight bullet-proof vests.

According to engineers at the Fraunhofer Technology Development Group TEG in Stuttgart the greatest potential for creating new products at the present time lies in harnessing the electrical properties of light and robust nanotubes to generate heat. Potential applications range from electric blankets and heatable aircraft wings that no longer ice up, through to wallpaper heating for cold walls.

Not to be outdone by their nanotube cousins, the buckyball, the only molecule composed of a single element, forms a hollow spheroid which is already a focus of attention by medical researchers.

The risks

Carbon nanotubes sound like a product designer’s dream. But like many technologies that offer benefits, there are risks which have to be addressed sensibly in order that the full benefits can be realized. We have all learned how to handle electricity, gas, steam and even cars and aeroplanes in a safe manner because we need their benefits. The same goes for carbon nanotubes. Mostly they will be perfectly safe, embedded within other materials, such as polymers. There is some possibility that free carbon nanotubes of a specific length scales may pose health threats if inhaled, particularly at the manufacturing stage. Industry is very conscious of this possibility, and is trying to ensure that any potential danger is minimized, so that we can all reap the benefits and promise of this new wonder material.