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Zigzag, armchair, and different types of chiral single-walled carbon nanotubes (SWCNTs) have distinct structures, due to different wrapping vectors of the underlying graphene sheets. The electronic properties depend on their structure, but this is less clear with regard to their mechanical properties. We modeled the first four flexural thermal vibrational modes of all three types with clamped ends, as a function of length. We applied a carefully equilibrated molecular dynamics procedure that was previously validated by comparison with the Timoshenko beam model in suitable limits. This analytic model allows for both rotary inertia and shearing deformation, but it cannot differentiate among the three atomistic structures. Comparison between the vibrational behavior of the three types of nanotubes clearly shows that the SWCNT structure does not affect the vibrational frequencies under clamped conditions.

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Low-field mobility in ultrathin silicon nanowire junctionless transistors Appl. Phys. Lett. 99, 233509 (2011) Influence of cross-section geometry and wire orientation on the phonon shifts in ultra-scaled Si nanowires J. Appl. Phys. 110, 094308 (2011) Thermal transport in double-wall carbon nanotubes using heat pulse J. Appl. Phys. 110, 074305 (2011) Phonon coherent resonance and its effect on thermal transport in core-shell nanowires J. Chem. Phys. 135, 104508 (2011) Single mode phonon energy transmission in functionalized carbon nanotubes Single-walled carbon nanotubes (SWCNTs) have three distinct structures: armchair, zigzag, and chiral. It is known that they have different electronic properties, but the situation regarding their vibrational behavior is less clear. Doubly clamped nanotubes of all three types exhibit the same vibrational modes, and their vibrations in the directions perpendicular to the nanotube axis are degenerate. In nanotube applications, such as sensors based on nano-electro-mechanical systems, their ends are not fully clamped, thus their vibrational behavior could differ. Careful molecular dynamics simulations of SWCNTs with boundary conditions, which imitate the partly clamped experimental conditions, show that armchair, zigzag, and chiral nanotubes indeed vibrate differently. The symmetry between the two perpendicular directions is broken, and SWCNT type does influence the vibrational modes.

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