CNTs, for example, can behave like an electrical conductor or a semiconductor, depending on the diameter and the twist of the tube. Nanoparticles have their own unique characteristics. Once attached to CNTs, they can transfer their abilities to the tube.
Nanoparticles could potentially give an insulator like silicon the ability to conduct electricity.
A happy union of the two structures offers a chance to brainstorm new applications, says Chen. For example, the hybrid can be altered to absorb and emit various wavelengths of light, giving it optical properties.
You get an opportunity to make a material that could potentially display not only the properties of the CNT and the nanoparticles, but also some additional properties because of the interaction between the two.
So one plus one may be greater than two, he says. Thats the whole idea.
Molecular building with control
Before Chens technique for fusing the two nanostructures, the process took hours.
CNTs are produced in a gas phase from carbon precursors, but nanoparticles are made in a solution, he says. You had to combine the dry with the wet before you can make something out of it, he says. Its not very compatible.
Also the surface of each structure had to be modified, and the chemistry would be different for each new material involved.
What you would get at the end could be very different from what you were trying to get, he says.
So Chen and his lab developed a way to make nanoparticles in the gas (dry) phase. Then they applied an electrostatic force to attract any kind of nanoparticle to the CNT. The one-step process takes only minutes.
It works like an indoor air cleaner, using the electric field to capture dust particles, he says.
Another advantage of the process is Chen can control the size of the nanoparticle that is fastened to the tube, and that determines the final propertie
|Contact: Junhong Chen|
University of Wisconsin - Milwaukee