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Pretreatment control of carbon nanotube array growth for gas separation: alignment and growth studied using microscopy and small-angle X-ray scattering.
- Source :
-
ACS applied materials & interfaces [ACS Appl Mater Interfaces] 2013 Apr 24; Vol. 5 (8), pp. 3063-70. Date of Electronic Publication: 2013 Apr 11. - Publication Year :
- 2013
-
Abstract
- Aligned multiwalled carbon nanotube (CNT) arrays were prepared using chemical vapor deposition of C2H4 on Fe catalyst at 750 °C. CNT array height and alignment depends strongly on the duration of H2 pretreatment, with optimal height and alignment achieved using 10-15 min pretreatment. Small-angle X-ray scattering (SAXS) was used to quantify the alignment, distribution, and size of the CNTs in arrays produced from varying pretreatment times and the results correlated with microscopy measurements. SAXS analysis revealed that the higher section of the CNT arrays exhibited better alignment than the lower section. Combining these insights with transmission electron microscopy measurements of the CNT defects within each array enable a mechanism for the CNT growth to be proposed, where the loss of alignment arises from deformation of the CNTs during their growth. Gas permeation test across densified CNT arrays indicated that the alignment of the CNT array plays an important role in the gas transport, and that the gas diffusion across the well-aligned CNT arrays was enhanced by a factor of ~45, which is much more than that across the poorly aligned CNT arrays, with an enhancement factor of ~8.
Details
- Language :
- English
- ISSN :
- 1944-8252
- Volume :
- 5
- Issue :
- 8
- Database :
- MEDLINE
- Journal :
- ACS applied materials & interfaces
- Publication Type :
- Academic Journal
- Accession number :
- 23517303
- Full Text :
- https://doi.org/10.1021/am3032579