Untitled

Growth of Carbon Nanotubes by Pyrolysis of Composite Film of Poly (Vinyl Alcohol) and Modified Fly Ash

“…The IG/ID ratio of the CNT materials grown on FA surfaces was 3.43, higher than the 1.17 for MWCNTs yielded for iron-catalyst-coated FA by the CVD method [6]. The line width and intensity ratio of (IG/ID) varied depending on the structure of the carbons and the conditions used for analysis, e.g., laser power and energy [11]. The well-known phenomenon, Raman band intensities and widths, increased with the decrease of wavelength of exciting laser, whereas these lines were shifted to lower wave number regions with an increase of the exciting laser power [12,13].…”

“…We presented a simple and in-situ environmentally friendly method for self-assembled CNT ropes with indefinitely long and highly flexible permanent twisted microscopic structures in TEM images in Figures 4 (a)-(b). In term of growth mechanism, several models have been proposed by the decomposition of hydrocarbon on metal surfaces [3,11], although the exact modes of action are still hypothetical.…”

Analysis of Carbon Nanotubes Produced by Pyrolysis of Composite Film of Poly (Vinyl Alcohol) and Modified Fly Ash

“…As discussed before, oxygencontaining functional groups grafted at CNT are likely to have been the precursors of the acetate nucleation sites in the PVA backbones. The different types of functionalized carbons are bridged in CNT graphite sheets by other systems and validated with XPS spectra [3,22].…”

“…The broadening of the bands relates to the defect and curvature of the CNT ropes because of the enhancement of the electron-phonon coupling [22]. The increase of electron-phonon coupling generally results from the admixture of sp 3 to sp 2 bonded carbon atoms [23].…”

“…In term of growth mechanism, several models have been proposed by the decomposition of hydrocarbon on metal surfaces [8,22], although the exact modes of action are still hypothetical. The mechanism of CNT growth was studied with respect to carbon dissolution in a metal catalyst.…”