Synthesis of beaded and entwined carbon nanofibers in Ni : Al alloy catalyst

This paper reports two new types of carbon nanofibers synthesis by thermal decomposition of n-hexane in presence of Ni-Al alloy in hydrogen atmosphere at 1100 degrees C. One type is "beaded fibers" in which spherical carbon beads (similar to 1 mu m) are regularly grown from outer surface of fibers (similar to 0.3 mu m). The other new microstructure is "entwined fibers" in which multiple nanofibers of diameter similar to 100 nm grow self-entwined like a braid of hair. Both bead-fiber bonding (in beaded fibers) and fiber-fiber interaction (in entwined fibers) are strong to be detached/unfolded by 30-min ultrasonication