What is a carbon nanotube?
How do you synthesize carbon nanotube arrays?
- Synthesis. Vertically aligned carbon nanotube arrays are also grown by thermal chemical vapor deposition. A substrate (quartz, silicon, stainless steel, etc.) is coated with a catalytic metal (Fe, Co, Ni) layer. Typically that layer is iron, and is deposited via sputtering to a thickness of 1–5 nm.
How do you make carbon nanotubes with CVD?
- In the CVD process, manufacturers can combine a metal catalyst (such as iron) with carbon-containing reaction gases (such as hydrogen or carbon monoxide) to form carbon nanotubes on the catalyst inside a high-temperature furnace. Schematic view of CNT growth on catalyst particles during CVD.
What is the difference between single-walled and multi-walled carbon nanotubes?
- CNTs can be single-walled (SWCNT) if made from one layer of carbon atoms, or multi-walled (MWCNT) when consisting of several layers of graphene sheets. In fact, carbon nanotubes come in various diameters, lengths, and functional group content which can tailor their use for specific applications.
What is the thinnest single-walled carbon nanotube?
- The thinnest freestanding single-walled carbon nanotube is about 0.43 nm in diameter. Researchers suggested that it can be either (5,1) or (4,2) SWCNT, but the exact type of the carbon nanotube remains questionable.
Are carbon nanotubes dangerous to human health?
- Carbon nanotube. Some researchers have become concerned about the health risks involving carbon nanotubes, which according to lab research seem to pose a danger to human health that is similar to asbestos. In particular, exposure to carbon nanotubes has been associated with mesothelioma, a cancer of the lung lining.
What are the environmental concerns of nanotubes?
- Environmental concerns. The environmental risks of nanotubes are still unclear. Naturally occurring carbon is fairly benign, and is largely unregulated, but nanotubes interact with the environment differently. There have been several studies performed to test the effects of carbon nanotubes on living systems.
What are the sidewalls of carbon nanotubes made of?
- The sidewalls of carbon nanotubes are made of graphene sheets consisting of neighboring hexagonal cells. Other polygon structures, such as pentagons and heptagons, constitute defects of sidewalls.
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