Molecular Dynamics Simulations and Theoretical Model for Engineering Tensile Properties of Single-and Multi-Walled Carbon Nanotubes | JoVE Visualize

Molecular Dynamics Simulations and Theoretical Model for Engineering Tensile Properties of Single-and Multi-Walled Carbon Nanotubes

Keiichi Shirasu¹, Shunsuke Kitayama², Fan Liu²

¹Department of Aerospace Engineering, Tohoku University, 6-6-01, Aza-Aoba, Aramaki, Aobaku, Sendai, Miyagi 980-8579, Japan.

Nanomaterials (Basel, Switzerland)|April 3, 2021

View abstract on PubMed

Summary

Molecular dynamics simulations reveal that carbon nanotubes (CNTs) with six to nine layers can achieve a nominal strength of 20 GPa. This finding addresses challenges in composite reinforcement by clarifying defect impacts on CNT strength.

Area of Science:

Materials Science
Nanotechnology
Computational Physics

Background:

Carbon nanotubes (CNTs) are promising reinforcing agents for advanced composites.
Improving the nominal strength of CNTs is crucial for their application.
Defects, such as vacancies, significantly impact CNT mechanical properties, complicating synthesis guidelines.

Purpose of the Study:

To investigate the influence of vacancies on the mechanical properties of CNTs.
To theoretically determine the relationship between the number of nanotube layers and effective/nominal strengths.
To provide guidelines for enhancing CNT nominal strength for composite applications.

Main Methods:

Molecular dynamics simulations were employed to model CNT behavior.
Theoretical analysis was conducted to establish relationships between layer number and strength.
The impact of vacancies on effective and nominal strengths was quantified.

Main Results:

Extensive vacancies in CNTs correlate with previously observed low nominal strengths.
CNTs with six to nine layers can achieve a nominal strength of approximately 20 GPa.
This multi-layered approach is more advantageous than double-walled CNTs requiring higher effective strengths.

Conclusions:

Vacancies are a key factor limiting the nominal strength of carbon nanotubes.
Optimizing the number of nanotube layers offers a viable strategy to significantly enhance composite reinforcement capabilities.
The study provides critical insights for designing stronger CNT-based materials.