Microwave Makes Carbon Nanotubes Less Defective

An ultrafast microwave annealing process has been developed to reduce the defect density in vertically aligned carbon nanotubes (CNTs). Raman and thermogravimetric analyses have shown a distinct defect reduction in the CNTs annealed in microwave for 3 min. Fibers spun from the as-annealed CNTs, in comparison with those from the pristine CNTs, show increases of similar to 35% and similar to 65%, respectively, in tensile strength (similar to 0.8 GPa) and modulus (similar to 90 GPa) during tensile testing; an similar to 20% improvement in electrical conductivity (similar to 80000 S m(-1)) was also reported. The mechanism of the microwave response of CNTs was discussed.