TY - GEN
T1 - Solution-Phase Surface Reconstruction and Structural Transformation in MWNTs
AU - Subramanian, Arunkumar
AU - Dong, Lixin
AU - Xu, Didi
AU - Nelson, Bradley J.
PY - 2009/6
Y1 - 2009/6
N2 - We report on structural changes induced in arc-grown multiwalled carbon nanotubes (MWNTs) due to ultrasonic agitation in an aqueous iron nitrate solution. The surface reconstructions were observed to follow three different pathways: (1) transformation from a tubular to a spherical / polyhedral onion-like geometry that involves a lower surface energy, (2) surface reconstruction of shells resulting in NT shrinkage from a larger diameter tube with a hollow core to a smaller diameter one with a solid core, and (3) the creation of highly reactive atomic-scale vacancies on carbon shells with low activation energies in the case of remaining NTs with a hollow core. Upon electron irradiation at extremely low beam intensities (1-2 A/cm2), the NTs with a hollow core have been observed to undergo structural reconstructions that result in shell shrinkage. The demonstrated techniques provide the capability to produce carbon onions in large-scale quantities and allow precision engineering of the geometry of condensed carbon allotropes. In addition, these results offer a route towards creating NTs with increased current densities / specific strength.
AB - We report on structural changes induced in arc-grown multiwalled carbon nanotubes (MWNTs) due to ultrasonic agitation in an aqueous iron nitrate solution. The surface reconstructions were observed to follow three different pathways: (1) transformation from a tubular to a spherical / polyhedral onion-like geometry that involves a lower surface energy, (2) surface reconstruction of shells resulting in NT shrinkage from a larger diameter tube with a hollow core to a smaller diameter one with a solid core, and (3) the creation of highly reactive atomic-scale vacancies on carbon shells with low activation energies in the case of remaining NTs with a hollow core. Upon electron irradiation at extremely low beam intensities (1-2 A/cm2), the NTs with a hollow core have been observed to undergo structural reconstructions that result in shell shrinkage. The demonstrated techniques provide the capability to produce carbon onions in large-scale quantities and allow precision engineering of the geometry of condensed carbon allotropes. In addition, these results offer a route towards creating NTs with increased current densities / specific strength.
KW - Carbon nanotube
KW - Carbon onion
KW - Reconstruction
KW - Surface transformation
UR - https://www.scopus.com/pages/publications/70449700543
UR - https://www.scopus.com/record/pubmetrics.uri?eid=2-s2.0-70449700543&origin=recordpage
U2 - 10.1109/NMDC.2009.5167581
DO - 10.1109/NMDC.2009.5167581
M3 - RGC 32 - Refereed conference paper (with host publication)
SN - 9781424446957
T3 - IEEE Nanotechnology Materials and Devices Conference, NMDC
SP - 174
EP - 177
BT - 2009 IEEE Nanotechnology Materials and Devices Conference
PB - IEEE
T2 - 2009 IEEE Nanotechnology Materials and Devices Conference, NMDC 2009
Y2 - 2 June 2009 through 5 June 2009
ER -