Highly compressible carbon nanowires synthesized by coating single-walled carbon nanotubes

Carbon nanowires with a diameter of 40-60 nm were synthesized by coating single-walled carbon nanotubes (SWCNTs) in an intermittent, one-stage DC arc discharge process. Transmission electron microscopy shows that these nanowires consist of a SWCNT with an amorphous carbon coating, whose thickness depends on the time of arc discharge. The mechanical properties of blocks of these nanowires were tested by load-unload cyclic compression and static force thermomechanical experiments. The results show that carbon nanowire blocks exhibit better compressive behavior than pure SWCNTs blocks, and carbon nanowires show a typical nonlinear strain-temperature response due to the amorphous carbon layer. A mechanism of adsorption-controlled growth of amorphous carbon on the SWCNTs in the vapor phase is proposed for the formation of the nanowires. (C) 2011 Elsevier Ltd. All rights reserved.