Nanostressing and Mechanochemistry
Kevin D. Ausman, Mead M. Jordan, Henry W. Rohrs, MinFeng
Yu, Rod S. Ruoff*
aDepartment of Physics, Washington University, St. Louis, MO 63130-4899
This is an abstract
for a presentation given at the
Sixth
Foresight Conference on Molecular Nanotechnology.
The full article is available at http://www.foresight.org/Conferences/MNT6/Papers/Ausman/index.html.
Controlled mechanical manipulation and testing of nanostructures
will be essential to the development and refinement of components for
nanotechnology applications. We are developing a stage to apply
controlled forces/displacements along one axis on nanoscale
materials. When applying tensile stress, this stage will allow
determination of elasticity, yield-point, and tensile strength of
nanoscale components or materials. Some of these properties have been
measured for multi-walled carbon nanotubes by other methods involving
thermal vibrations1 or lateral bending2, but
for geometric reasons the off-axis mechanical properties of carbon
nanotubes are likely to be different from the on-axis properties.
When the proposed stressing stage is used to apply compressive
stress, bending, kinking, and buckling may be observed. In this talk,
we report progress toward the development of this single-axis
nanostressing stage, which is designed for use with transmission
electron microscope imaging.
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One of the primary driving forces for chemical reactivity
in the fullerenes is the release of cage strain energy
caused by cage-induced curvature of the normally planar
sp2 hybridized carbons.3 In fact, it
is observed that in carbon nanotubes, the highly curved end
caps are more reactive than the less curved side
walls.4,5,6 Several studies have observed that
carbon nanotubes may be reversibly kinked, much as a common
garden hose may be, producing areas of high localized
curvature.7,8,9,10 It follows that these highly
curved sites will be preferentially reactive in the same
types of reactions that have been successful on fullerenes
and nanotube end caps. However, these kinked sites are
predicted to have even higher degrees of curvature than the
end caps and the fullerenes11, and thus are
likely to be even more reactive.12
In order to experimentally perform mechanochemistry on
carbon nanotubes, as we term the controlled induction of
chemical reactions by nanoscale mechanical stresses, we must
be able to reliably kink the tubes. We hope to eventually do
this with the nanostressing stage described above. However,
we have already been able to kink nanotubes by AFM
manipulation. Progress toward mechanochemistry on AFM kinked
nanotubes will be reported.
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References
[1] Treacy, M.M.J.; Ebbesen, T.W.; and Gibson, J.M. (1996) Nature,
381, June 20, pages 678-680. Exceptionally high Young's modulus
observed for individual carbon nanotubes
[2] Wong, E.W.; Sheehan, P.E.; and Lieber, C.M. (1997) Science,
277, September 26, pages 1971-1975. Nanobeam Mechanics: Elasticity,
Strength, and Toughness of Nanorods and Nanotubes
[3] Haddon, R.C. (1993) Science, 261, September 17, pages
1545-1550. Chemistry of the Fullerenes: The Manifestation of Strain
in a Class of Continuous Aromatic Molecules
[4] Tsang, S.C.; Harris, P.J.F.; and Green, M.L.H. (1993) Nature,
362, April 8, pages 520-522. Thinning and opening of carbon nanotubes
by oxidation using carbon dioxide
[5] Tsang, S.C.; Chen, Y.K.; Harris, P.J.F.; and Green, M.L.H.
(1994) Nature, 372, November 10, pages 159-162. A simple chemical
method of opening and filling carbon nanotubes
[6] Hwang, K.C. (1995) Journal of the Chemical Society, Chemical
Communications, January 21, pages 173-174. Efficient Cleavage of
Carbon Graphene Layers by Oxidants.
[7] Despres, J.F.; Daguerre, E.; and Lafdi, K (1995) Carbon, 33
No. 1, pages 149-151. Flexibility of graphene layers in carbon
nanotubes.
[8] Kuzumaki, T.; Hayashi, T.; Ichinose,H.; Miyazawa, K.; Ito, K.;
and Ishida, Y. (1998) Philosophical Magazene A, 77 No. 6, pages
1461-1469. In-situ observed deformation of carbon nanotubes
[9] Yakobson, B.I.; Brabec, C.J., and Bernholc, J. (1996),
Physical Review Letters, 76 No. 14, April 1, pages 2511-2514.
Nanomechanics of Carbon Tubes: Instabilities beyond Linear Response
[10] Cornwell, C.F. and Wille, L.T. (1998) Journal of Chemical
Physics, 109 No. 2, July 8, pages 763-767. Critical strain and
catalytic growth of single-walled carbon nanotubes
[11] Iijima, S.; Brabec, C.; Maiti, A.; and Bernholc, J. (1996)
Journal of Chemical Physics, 104 No. 5, February 1, pages 2089-2092.
Structural flexibility of carbon nanotubes
[12] Srivastava, D.; Brenner, D.W.; Schall, J.D.; Ruoff, R. (in
preparation) Kinky Chemistry: Predictions of Enhanced Chemical
Binding to Fullerene Tubules at Kink Sites
*Corresponding Address:
Rodney S. Ruoff
Physics Department, Washington University
CB1105, One Brookings Drive, St. Louis, MO63130-4899.
Tel: (314) 935-7507, fax (314) 935-5258
Email: [email protected], Web:
http://bucky5.wustl.edu/
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