Understanding the nanoscale local buckling behavior of vertically aligned MWCNT arrays with van der Waals interactions

Abstract

The local buckling behavior of vertically aligned carbon nanotubes (VACNTs) has been investigated and interpreted in the view of a collective nanotube response by taking van der Waals interactions into account. To the best of our knowledge, this is the first report on the case of collective VACNT behavior regarding van der Waals force among nanotubes as a lateral support effect during the buckling process. The local buckling propagation and development of VACNTs were experimentally observed and theoretically analyzed by employing finite element modeling with lateral support from van der Waals interactions among nanotubes. Both experimental and theoretical analyses show that VACNTs buckled in the bottom region with many short waves and almost identical wavelengths, indicating a high mode buckling. Furthermore, the propagation and development mechanism of buckling waves follow the wave damping effect.

Energy dissipation in intercalated carbon nanotube forests with metal layers

“…The wavelength may change as a function of depth because of the nature of forests as functionally graded. Eventually, the folds are expected to stop due to a wave damping effect [32]. After the first cycle, the roughness in the stress versus strain curves significantly decreases, indicating that most of these folds are developed during the first cycle where the full range of stress and strain is first applied.…”

“…4. The wavelength of the local buckling folds is a function of the CNT structure, Young's modulus, aspect ratio, and van der Waals interaction and constraining forces [32,33]. They indicate that the CNT forest structure may be characterized as an open cellular foam structure [34].…”

Vibration Damping of Carbon Nanotube Assembly Materials

“…Although CNT is a super‐elastic material with a modulus up to TPa scale, it can still cost energy by structural deformation such as buckling and collapsing. Thus, the tube itself can exhibit inherent viscoelasticity in some cases like the compression on CNT forests . Thus, there could be a strategy to make CNT assemblies more viscoelastic by modifying the nanotube structure, for example, introduction of defects that cause more dissipation under interfacial sliding, changing straight tube structure into helical, and so on.…”

“…Different from metals and polymers, the CNT assembly materials possess rich contacts, connections, cross‐links, and thus different types of interfaces between the nano components. For example, zipping/unzipping of adjacent CNTs, sliding between CNTs or CNT bundles, buckling of CNTs, and self‐organization upon loading have become the main sources of viscoelasticity for the assembly materials …”

Vertically Aligned Carbon Nanotubes as Platform for Biomimetically Inspired Mechanical Sensing, Bioactive Surfaces, and Electrical Cell Interfacing

“…In contrast, far much less efforts have been devoted to experimental and theoretical stress/strain studies in transversal, lateral deformation studies of VACNTs (see, e.g., Figure 4 ). The bending situation which occurs upon such a mechanical distortion of a VACNT array is shown schematically in Figure 5 . Typically, VACNTs show a straight tube alignment in the middle and an entanglement of individual tubes in the top region of such an array (Figure ).…”