|    Emerging methods to produce carbon  nanotubes, which have potential applications in fields as varied as molecular  electronics and performance materials, are generating considerable excitement  in the scientific community.   Scientists worldwide are conducting  extensive research on these carbon forms, which are excellent conductors and  provide useful strength and electrical properties.   Commonly produced through methods such as  arc discharge, laser ablation, or chemical vapour deposition, nanotubes can  also be produced by ball milling, hydrothermal pressure, decomposition of  buckyballs, and annealing of soot. However, obtaining large enough quantities  of the material continues to be one of the biggest challenges facing  nanotechnology researchers.   “To realize their full potential, carbon  nanotubes need to be available inexpensively and abundantly,” says Technical  Insights Analyst Aninditta Savitry.   Nanotube manufacturing typically produces  only 10 mg of nanotubes, but a newly developed approach promises to form  trillions within an hour. This method, which involves striking a  metal-impregnated carbon target with free-electron laser light, promises to  reduce the production cost of nanotubes to $100 per gram from that of $200  per gram using other methods.   “Less expensive nanotubes will enable a  wider range of possible applications,” notes Savitry. “Bringing down  production costs is an immediate challenge that needs to be addressed.”   Many nanotube production methods exist.  One method involves sprouting nanotubes from particulate seeds of an iron and  molybdenum catalyst. The process takes place in a chemical vapour deposition  chamber where heat and catalysts decompose hydrocarbons.   Some scientists are searching for even  more suitable catalysts for growing nanotubes. High-throughput  experimentation, for example, holds promise in the pursuit of the most  practical catalyst for producing nanotubes with specific properties.   Carbon nanotubes are expected to have a  strong impact on our day-to-day life once they are available in large amounts  and properly functionalized. Scientists and engineers will then be able to  work on getting these useful materials into practical working systems.   “We’ve already seen some significant  developments, not only in the electronics sector, but also in the materials,  medical, and biotechnology sectors," says Savitry. “Nanotubes may one  day be used to create biosensors or enhance the toughness of ceramics."    |