Double-wall carbon nanotubes (DWCNTs) and single-wall carbon nanotubes (SWCNTs) have been synthesized by the DC abnormal glow discharge plasma CVD method using methane and hydrogen gas on a Si substrate coated with catalyst. Fe(NO3)2 and Mo(CH3COCHCOCH3)2O2 with Al2O3 support were used as catalysts. The growth temperatures were 1000 − 1400°C and the gas pressures were 9kPa - 13kPa. DC plasma was generated between an array of four W cathodes and a Cu disk anode, and the applied power was 4000–10000W (2.5–4.0A per cathode, 400–800V). Samples were characterized by high-resolution transmission electron microscopy (HRTEM) and micro-Raman spectroscopy using 514.5 nm Ar ion laser excitation. The HRTEM images showed that many carbon nanotubes had a concentric cylindrical graphene layer structure (DWCNTs). We measured the diameters of the carbon nanotubes (CNTs) from HRTEM images. The outer diameter of the DWNT was 1.52–1.64nm and the inner diameter of the DWNT was 0.73–0.81nm.

Fine molecular straw, carbon nanotube (NT) is aligned to form a bundle. The purified NTs are mixed with a plastic polymer (polypropylene: PP) and extruded from a small die with a diameter of 2 mm kept at 200°C. The threads of NT/PP blend are characterized by small angle X-ray diffractometry and transmission electron microscope to confirm the existence of nanobundle of NTs, which orient along the spinning direction.