A research team from Waseda University has just demonstrated their latest carbon nanotube (CNT) cluster growth technology. The new solution can generate carbon nanotube bundles up to 14 cm (5.5 inches) long, or may help simplify future mass production processes. It is reported that the diameter of carbon nanotubes is only a few nanometers, and it has shown eye-catching prospects in the fields of light and strong materials, optics/water filtration/battery/transistor, etc.
Previously, a major obstacle to the application of carbon nanotubes was the difficulty of mass production. Although previous research teams have managed to grow a single carbon nanotube to 50 cm (19.7 inches), the practicality is still quite limited.
After focusing on the carbon nanotube (CNT) clusters, the relevant research team has also been trying to break through the 2 cm (0.8 inch) limit, until we suddenly saw the 14 cm (5.5 cm) from Waseda University.
In order to achieve this goal, the research team first needs to solve the problem of catalyst degradation in the pipeline. Study author Hisashi Sugime points out:
"Under conventional technology, the structure of the catalyst will gradually change, eventually causing the CNT to stop growing. For this reason, we have focused on how to suppress this structural change to support the new technology of long-term CNT growth."
Specifically, the researchers added a new layer of material on the silicon substrate coated with iron and aluminum oxide, thereby slowing the degradation rate of the catalyst. However, if only this solution is used, the CNT bundle can only be grown to about 5 cm (2 inches).
Secondly, the research team thought of putting the catalyst into a chemical vapor deposition chamber. After the catalyst was heated to 750°C (1382°F), a small amount of iron-aluminum vapor was added at room temperature, which finally extended the catalyst's effectiveness to 26 hours.
More importantly, through the analysis of the newly formed carbon nanotube bundle, it can be seen that its performance and purity are almost the same as other methods. Details of this research have been published in the recently published "Carbon" journal.
The original title is "Ultra-long carbon nanotube forest via in situ supplements of iron and aluminum vapor sources".