A carbon nanotube formation process of producing carbon nanotubes includes controlled heating of plant fiber materials in an oxygen-limited atmosphere. The activation process is sequentially performed within plural containers having different atmospheres. In one embodiment, the polymer composite has an electrically conductive filler and can be used in a filament for treating arteriovascular malformations. The unsaturated alkyl alcohol can be further reduced, if desired, to produce a saturated alkyl alcohol. The complex may be used also for treating mammalian cancer which is not responsive to increased production of cytokines.