A thermal treatment was applied with CO2 and air for the development of a porous structure. Adsorption isotherms of nitrogen were measured on well-characterized Ni-C nanoparticles. The thermal treatment with CO2 increased the total surface area and micropore volume. In addition, the thermal treatment with CO2 increased the hydrogen adsorption.

Aligned multi-wall carbon nanotubes (MWNTs) were successfully grown on a Si substrate based on a thermal chemical vapor deposition (CVD) method. We employed Co metal nanoparticles as the catalyst for nanotube growth, which were prepared by a reverse micelle method. The reverse micelle method provides nanoparticles covered with surfactants so that they are dispersed in organic solvent and, thus highly processible. The present MWNT arrays are promising for application in field emission displays, because of much lower nanotube density compared with the previously reported arrays.

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.

Purification process to obtain nanotubes out of the cathode product mostly including fragments of graphitic sheet and/or amorphous carbon has been established. Structures and electronic properties of carbon nanotubes were studied. By the Raman scattering measurement, only one peak at 1581 cm−1 akin to that of graphite was found out. It was confirmed by STM observation of purified nanotubes. Purified nanotubes was semiconductor or semimetal.