Mechanical properties of methyl functionalized single-walled carbon nanotube

• Main Author: Goh, Ivan Peck Chen.
• Other Authors: Dong Zhili
• Format: Final Year Project
• Language: English
• Published: 2011
• Subjects: DRNTU::Engineering::Materials::Nanostructured materials; DRNTU::Engineering::Materials::Mechanical strength of materials
• Online Access: http://hdl.handle.net/10356/44076
• Institution: Nanyang Technological University

Molecular dynamics simulations have been conducted to investigate the effect of methyl (CH3) functionalization on the mechanical properties of single-walled carbon nanotubes (SWCNT). Small numbers of CH3 radicals were chemically absorbed on SWCNT in two ways: axially and circumferentially. It is found that for axial functionalization, the tensile properties of SWCNT will decrease by about 15% after the first CH3 radical is added. Further addition of CH3 had less effect on the tensile properties. Addition of CH3 group only has significant effect on the compressive properties of the SWCNT when more than 1 CH3 group is added. The effect of circumferential functionalization on the mechanical properties of the SWCNT is found to be greater. The decrease in tensile strength and compressive strength is about 18% and 20% respectively. We also noted that the elastic modulus of the SWCNT is less sensitive to the effect of functionalization as compared to the tensile strength and fracture strain. Studies of the effect of temperature variation on the different SWCNT were also performed. Temperature tested were 10K, 300K, 500K and 1000K. We found that at higher temperature, the tensile strength, fracture strain, compressive strength and buckling strain drop by as much as 58.8%, 61.7%, 33.7% and 25.5% respectively. Our results suggest that the loss in the mechanical properties of functionalized SWCNT must be taken into account when evaluating the performance characteristics of SWCNT applications such as mass sensors and mechanical nanoresonators. Furthermore, the effect of temperature variation must also be accounted for its influence on the mechanical properties.