Close-packed carbon nanotubes, forming a three-dimensional nonwoven macroporous sponge-like network, are synthesized at 900 degrees C over a sol-gel Co-Mo-Mg catalyst using CH4 + He growth mixture with variable composition (CH4: 190-1000 sccm; He: 0-810 sccm). The samples consist of dense, randomly oriented bundles of tubes grown on and interconnected through catalyst fragments and entanglements of curly tubes. The relative amounts of the two network components depend on the gas-flowing setup selected. A systematic multiwavelength Raman spectroscopy analysis is carried out in order to investigate the tensional states arising from the interconnections among bundles. Results obtained are understood in terms of the morphology evolution produced by the catalyst phases with different activity involved in the growth process as an effect of the changes in the gas-flowing setup.
Micro-Raman Analysis of Three-Dimensional Macroporous Sponge-Like Network of Carbon Nanotubes under Tension
PIPEROPOULOS, Elpida;FAZIO, Enza;MILONE, Candida
2014-01-01
Abstract
Close-packed carbon nanotubes, forming a three-dimensional nonwoven macroporous sponge-like network, are synthesized at 900 degrees C over a sol-gel Co-Mo-Mg catalyst using CH4 + He growth mixture with variable composition (CH4: 190-1000 sccm; He: 0-810 sccm). The samples consist of dense, randomly oriented bundles of tubes grown on and interconnected through catalyst fragments and entanglements of curly tubes. The relative amounts of the two network components depend on the gas-flowing setup selected. A systematic multiwavelength Raman spectroscopy analysis is carried out in order to investigate the tensional states arising from the interconnections among bundles. Results obtained are understood in terms of the morphology evolution produced by the catalyst phases with different activity involved in the growth process as an effect of the changes in the gas-flowing setup.Pubblicazioni consigliate
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