Morphological Evolvement of Carbon Nanotubes Synthesized by Using Conducting Polymer Nanofibers

Figure 5

Different morphologies can be observed for the CNTs synthesized by 90 s microwave time, such as straight tubes with continuous tube walls (a), bamboo-shaped tubes with segmented tube walls (b), curved tubes with continuous tube walls (c), and cup-stack tubes (d). A few large rhombohedral and rectangular NPs can be observed in (c), (d), and (e), indicating substantial Ostwald ripening of the catalysts. Protruding (e) and liquid-shaped (f) catalyst Fe NPs can be observed at the tips of the as-obtained CNTs, indicating the same growth mode with the 30 s and 60 s processes.

(a)

(b)

(c)

(d)

(e)

(f)