It works! Thus the researchers have proved that, by using made-to-measure molecular "germs", it is possible to clearly predefine the growth (and thus the structure) of long SWCNTs. The SWCNTs synthesised in this study are mirror-image symmetrical entities. However, depending on the manner in which the honeycombed atomic lattice is derived from the starting molecule ("straight" or "oblique" in relation to the CNT axis), it would also possible be possible to produce helically-wound nanotubes, i.e. nanotubes twisting to the right or left, which are not mirror-image symmetrical. And this very structure also determines the electronic, thermoelectric and optical properties of the material. Therefore, in principle, the researchers can produce materials with different properties in a targeted manner, by selecting the starting molecule. As their next step, Fasel and his colleagues intend to gain an even better understanding of the way in which SWCNTs populate a surface. Although well over 100 million nanotubes per square centimetre are already grown on the platinum surface, actual "fully-grown" nanotubes only grow from a comparatively small proportion of the germs. This raises the questions: which processes are responsible for this, and how can the yield be increased? The project was supported by the Swiss National Science Foundation (FNSNF). |