Nanotubes fortify plastic film

Encasing carbon nanotubes in plastic has a lot of appeal. Nanotubes, rolled-up sheets of carbon atoms that are 1,000 times narrower than E. coli bacteria, are stronger than steel and have useful electrical properties. A polymer setting keeps microscopic nanotubes in place and makes for a material that is easy to handle.

Researchers from Trinity College in Ireland and Rensselaer Polytechnic Institute have developed an inexpensive process for making a nanotube-polymer composite that allows for close control of the density and position of the nanotubes.

The material can be used to reinforce plastic materials and could form the basis for many types of flexible electronic and mechanical devices, including sensors, field emitters and actuators, according to the researchers.

The researchers were able to precisely position nanotubes within plastic by growing the nanotubes on a surface first, then coating them with a polymer that was cured, or hardened, at room temperature, then, along with the nanotubes it encased, peeled off the surface.

To coax the nanotubes to grow in specific positions and concentrations on the surface, the researchers carved a pattern into a rubber stamp and used the stamp to place a catalyst for nanotube growth on the surface.

The nanotube-polymer composite films could be used practically in two to three years, according to the researchers. The work appeared in the October 8, 2003 issue of Nano Letters.