Can sientists can controll chirality in carbon nanotubes

Synthesising a single walled carbon nanotubes(SWNTs) with cotrolled chiralities is the challenge in the field of carbon nanotube research.

Single walled c-nanotube

Sientists have now abled to control chirality in c-nanotues using the chemical vapor deposition (CVD) synthesis after discovering of SWNTs 20 years ago.

 A pair of integers, chiral indices (n,m) is used to descirbe the c-nanotubes structure. so called chirality can explain the optical and electronic properties of c-nanotubes and then discribe its practical applications.

Sustantial research has been made to find synthesis methods and has been hindered by lack of practical methods to have the metal nanoparticle catalystd and its characteristic dynamics during tube groth.

The developed new catalyst has employed for selective growth of SWNTs in the conventional CVD reactor and the researchers have demonstrated preferential growth of semiconducting SWNTs (～90%) with an exceptionally high population of (6,5) tubes (53%) at 500 °C. Furthermore, they also showed a shift of the chiral preference from (6,5) tubes at 500 °C to (7, 6) and (9, 4) nanotubes at 400 °C.

These findings have opened new perspectives both for structural control of SWNTs and for elucidating their growth mechanisms, thus are important for the fundamental understanding of science behind nanotube growth.