Nanotechnology

Nanotechnology refers to the science and engineering of particles that are on the nanoscale, which is are about 1 to 100 nanometers (nm) in size. For comparison, the thickness of a sheet of paper is about 100,000 nm and the width of a hair, about 40,000 – 80,000 nm. Materials that exhibit a dimension below 100 nm have very different and interesting properties than the bulk material.  As an example, gold is a very inert metal, but below 100 nm, nanoparticles of gold possess properties that make them good catalysts and sensors.  With opportunities ranging from aerospace and defense to medical to sporting goods, nanotechnology will the change the face of innovation for generations to come.

What Are Carbon Nanotubes?


iStock_000077925055_Large.jpgCarbon nanotubes (CNTs) are best described as a seamless cylindrical hollow fibers, comprised of a single sheet of pure graphite (a hexagonal lattice of carbon, similar to a chain link fence), having a diameter of 0.7 to 50 nanometers with lengths generally in the range of 10’s of microns.  Being a hollow tube comprised entirely of carbon, they are also extremely light weight.

The type of bond holding the carbon atoms together is very strong, plus the hexagonal pattern of the atoms themselves gives rise to a phenomenon known as electron delocalization.   This means that under the right conditions electrical charge can move freely in a nanotube.   The regular arrangement of the atoms also can vibrate in ways that effectively move heat through the tube, so thermal conductivity is high as well as electrical. At the individual tube level, these unique structures exhibit: 200X the strength and 5X the elasticity of steel; 5X the electrical conductivity, 15X the thermal conductivity and 1,000X the current capacity of copper; at almost half the density of aluminum.

When CNTs were first discovered people believed that any length was good enough for real world applications.   However, it was soon learned that the relatively short lengths of these tubes (a small fraction of a millimeter) meant that when tubes were combined with other materials, unless they were added in very high (and costly) amounts, they wouldn’t connect and form a network.  Without the tubes forming a network, it was practically impossible to make a material that delivered the electrical, thermal, and mechanical performance that the individual tubes exhibited.

Nanocomp resolved this problem by developing  processes that generate tubes that are hundreds of times longer (>1mm) than those from other manufacturers form6-13-2012_1-38-40_PM.jpged into bundles.   When tubes get very close to each other, some of the electrons in each of the tubes begin synchronizing their motion so that the tubes actually stick together.   This attractive force – called a dispersion force­ ­ - does more than simply hold the tubes together.   As the tubes come together, the force also makes them intertwine with each other forming a network. This combined effect makes the sheets, yarns, and tapes made by Nanocomp much stronger than if they were made with the shorter tubes.   While the bulk material properties of Nanocomp’s MiralonTM products do not match those of the individual tubes described above, they are far superior to the loose tube powders being manufactured elsewhere.

Further, Miralon products are shipped as macro formats, comprised of many bundles of multi-millimeter long CNTs that are too long to be inhaled or absorbed by the skin. Due to this, they are classified by the Environmental Protection Agency (EPA) as "articles”, and "not" particles, unlike traditional CNT powders and loose tubes, making them safe to handle and process in commercial, industrial, and military applications.

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Visit nano.gov to learn more about nanotechnology.

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