Scientists develop way to control nanotube properties
Scientists from Finland, Russia and Denmark have managed to control chirality in carbon nanotubes during chemical vapour deposition (CVD) synthesis.
Because chirality defines the optical and electronic properties of carbon nanotubes, controlling it is seen to be key to exploiting their practical applications, according to Professor Esko Kauppinen from Aalto University's School of Science.
While progress has been made to develop various structure controlled synthesis methods for single walled carbon nanotubes (SWNTs), the chiral structure has been hindered by the inability to direct the formation of the metal nanoparticle catalysts and their catalytic dynamics during tube growth.
By introducing new catalysts into a conventional CVD reactor, the research team demonstrated preferential growth of semiconducting SWNTs (~90%) with an exceptionally high population of (6,5) tubes (53%) at 500°C. Lowering the temperature to 400°C saw a move to (7,6) and (9,4) nanotubes.
