Low-temperature, controlled synthesis of carbon nanotubes

The significant advances made in the low-temperature, controlled synthesis of carbon nanotubes for the development in the field of nanoscience and nanotechnology were discussed. Carbon tetrachloride (CCl4) was used with weaker carbon-halide bonds for the pyrolytic growth of multiwalled nanotubes (MWNT) in a supercritical carbon dioxide medium in the presence of iron catalysts encapsulated in polypropyleneimine (PPI) dendrimers. The high pressure exerted by carbon dioxide assisted in the decomposition of CCl 4 and facilitated the delivery of the intermediate species to the encapsulated iron surface for the nucleation and growth of carbon nanotubes at a record temperature. The results show that it was possible to produce carbon nanotubes of different diameters and structures by controlling the distribution of the catalyst iron nanoparticles within various dendritic structures.