Catalytic effects of metal carbides, oxides and Ni single crystal on the vapor growth of micro-coiled carbon fibers

Effect of synthesis method of nanocopper catalysts on the morphologies of carbon nanofibers prepared by catalytic decomposition of acetylene

“…Multidirectional carbon deposits were also observed in filaments formed on nickel catalysts of high sulfur content [8][9][10]. Motojima and co-workers prepared microcoiled carbon fibers by metal powder-activated pyrolysis of acetylene containing a small amount of H 2 S or thiophene as an impurity [11][12][13]. The effect of the metal catalyst source and presulfidation of the metals on the growth of the coiled carbon fibers were examined in detail.…”

Helical carbon nanofibers with a symmetric growth mode

“…These helical materials include helical carbon nanotubes [1], silicon carbon nanosprings [2], silica nanosprings [3][4][5], SiC-SiO 2 core-shell nanowires [6], and transition-metal oxide nanofibers such as TiO 2 [7,8]. Motojima et al reported the synthesis of micro-coiled carbon fibers by metal powder-activated pyrolysis of acetylene containing a small amount of H 2 S or thiophene as an impurity [9][10][11][12]. These coils were double-coiled forms in which two fibers entwined with each other such as double helix of a DNA.…”

Preparation and Characterization of Carbon Microcoils (CMCs)

“…From these results, we proposed the 3D-growth model of the carbon coils based on the catalytic anisotropy of the crystal faces of the catalyst grain. [16][17][18][19] Figure 9 shows the growth model of the circular carbon coils. In this model, the order of the catalytic activity for the carbon deposition among the three crystal faces is A > B > C. Basically, a carbon fiber is composed of fine carbon grains deposited from the three crystal faces of A, B, and C, and curls in such a way that the carbon grains deposited on crystal faces A and B are on the outer side of the coil, while the grains deposited on crystal face C are inside.…”