Catalytic chemical vapor deposition synthesis and electron microscopy observation of coiled carbon nanotubes

Coiled carbon nanotubes exhibit excellent mechanical and electrical properties because of the combination of coil morphology and properties of nanotubes. They could have potential novel applications in nanocomposites and nano-electronic devices as well as nano-electromechanical systems. In this work, synthesis of regularly coiled carbon nanotubes is presented. It involves pyrolysis of hydrocarbon gas over metal/support catalyst by both thermal filament and microwave catalytic chemical vapor deposition methods. Scanning electron rnicroscopy and transmission electron microscopy were performed to observe the coil morphology and nanostructure of coiled nanotubes. The growth mechanism and structural and electrical properties of coiled carbon nanotubes are also discussed.