By improving the catalyst, scientists made carbon nanotube bundles up to 14 cm long

A team of researchers at Waseda University has just demonstrated their latest carbon nanotube (CNT) cluster growth technology. The new scheme can generate carbon nanotube bundles up to 14 cm (5.5 inches) or help simplify future mass production processes. It is reported that the diameter of carbon nanotubes is only a few nanometers, in the lightweight and strong materials, optics / water filter / battery / transistor and other fields have shown remarkable prospects.

By improving the catalyst, scientists made carbon nanotube bundles up to 14 cm long

(From Waseda University)

One of the previous obstacles to carbon nanotube applications was the difficulty of mass production. Although previous research teams have managed to grow individual carbon nanotubes to 50 cm (19.7 inches), their usefulness is still limited.

After looking at the carbon nanotube (CNT) cluster, the team was also working to break the 2 cm (0.8 inch) limit until we suddenly saw 14 cm (5.5 cm) from Waseda University.

To achieve this, the research team first needs to address catalyst deterioratation in the pipeline. Study author Hisashi Sugime points out that:

“Under conventional techniques, the structure of the catalyst changes gradually, eventually causing CNT to stop growing. To this end, we focus on how to suppress this structural change in order to support the long-term growth of CNT in new technologies.”

By improving the catalyst, scientists made carbon nanotube bundles up to 14 cm long

Specifically, the researchers added a new layer of material to the silicon substrate coated with iron-aluminum oxides, slowing the catalyst’s degradation rate. However, with this scheme alone, the CNT bundle can only grow to about 5 cm (2 inches).

Second, the team came up with the idea of putting the catalytic converter into a chemical vapor deposition chamber. After heating the catalyst to 750 degrees C (1382 degrees F), a small amount of iron-aluminum steam is added at room temperature, which eventually extends the catalyst’s effectiveness to 26 hours.

What’s more, by analyzing the newly formed carbon nanotube bundles, it is clear that their properties and purity are almost different from among other methods. Details of the study have been published in the recently published journal Carbon.

Originally titled Ultra-long carbon nanotube forest via situ supplements of iron and aluminum vapor sources.