Diameter-dependent elastic modulus supports the metastable-catalyst growth of carbon nanotubes.
We measured the elastic modulus of individual multiwalled carbon nanotubes (MWCNTs) grown by catalytic chemical vapor deposition (CVD) over a broad diameter range (10-25 nm). Alternating current (ac) dielectrophoresis was used for efficient tube deposition, and atomic force microscope (AFM) force-displacement curve technique was used for stiffness measurements. The elastic modulus exhibits a strong diameter dependence, showing a difference of nearly 2 orders of magnitude in the 10-20 nm diameter range (thinner MWCNTs have higher elastic modulus). Our results support the metastable-catalyst model in which the catalyst's molten skin plays a key role.
Lee
Kyumin
K
Ecole Polytechnique Fédérale de Lausanne (EPFL), Institute of Physics of Complex Matter, 1015 Lausanne, Switzerland. lee.kyumin@gmail.com
Lukić
Branimir
B
Magrez
Arnaud
A
Seo
Jin Won
JW
Briggs
G Andrew D
GA
Kulik
Andrzej J
AJ
Forró
Laszló
L
D002384:Catalysis; D003198:Computer Simulation; D003460:Crystallization / Q000379:methods*; D004548:Elasticity; D004586:Electrophoresis / Q000379:methods*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008956:Models, Chemical; D008968:Molecular Conformation; D036103:Nanotechnology / Q000379:methods*; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D013314:Stress, Mechanical; D013499:Surface Properties
D046911:Macromolecular Substances; D037742:Nanotubes, Carbon