Carbon nanotubes as strong fibers in CNT-composites are subjected to large deformations in radial direction. They provide strength as well as structural damping in the composite. Despite being strong in the axial direction, CNTs are rather soft in the radial direction.
We recently measured large deformation up to complete flattening of individual MWCNTs in the radial (transverse) direction. The results reveal that CNTs exhibit reversible deformation up to 60% strain. In addition we measured structural damping of individual MWCNT. As a hallow nanostructure, MWCNTs show tangent modulus on the order of ~0.06 which is comparable to the common polymers such as HDPE.
These results can be useful in computational models of CNT-composites when properties of an individual CNT in the radial direction is required.
- Reversible radial deformation up to the complete flattening of carbon nanotubes in nanoindentation, J. Appl. Phys. 103, 073516 (2008).
- An improved in situ measurement of offset phase shift towards quantitative damping-measurement with AFM, Ultramicroscopy, In Press.