Читать книгу Carbon Nanofibers - Группа авторов - Страница 25

Carbon nanofibers (CNFs) were first reported by Hughes and Chambers in a patent in 1889 [5] while carrying out the synthesis of filamentous carbon. Pyrolysis of methane/hydrogen gaseous mixture yielded carbon nanofibers in the form of a filament growth. The first electron microscopy observations of hollow carbon nanofibers of 50 nm in diameter was reported in the early 1950s by the Soviet scientists Radushkevich and Lukyanovich. Then, in 1988 Morinobu Endo [6] at Shinshu University, Japan, reported carbon nanofibers with a diameter of 1 μm and length of above 1 mm. In 1991, Yoshinori Ando [7] synthesized carbon nanomaterial by Arc process which was examined by Sumio Iijima while working at NEC as a new form of carbon nanotube. Pradhan synthesized carbon nanofibers by the pyrolysis of precursor camphor. Some of the peculiar shaped carbon nanofibers synthesized are shown in Figure 1.6.

Figure 1.6 (a) TEM image showing graphene layers of (b) entwined carbon nanofibers synthesized at 1100 °C in presence of Ni: Al catalyst and n-hexane; (c, d) TEM images of open-ended bent, V-shaped inner novel growth of carbon nanotubes at 1000 °C in presence of nickel particles; and (e) SEM micrograph image of straight VGCFs (Source: Debabrata Pradhan, 2003) [4].