Elastic Moduli Of Single-walled Carbon Nanotubes Research Articles

Effect of Stone–Wales and vacancy defects on elastic moduli of carbon nanotubes and their composites using molecular dynamics simulation

Carbon nanotubes (CNTs) containing no defect exhibit excellent mechanical properties. However, CNTs suffer from defects such as vacancies, hybridization, doping and Stone–Wales (SW) defects which can appear during purification, production or can be deliberately introduced using chemical treatment. The study conducted here is based on comparative investigation of effect produced by SW and vacancy defects on the elastic moduli of SWCNTs. A (4,4) armchair SWCNT has been used in this study and the number of defects is varied from 1 to 4. Molecular dynamics (MD) simulation has been used to study the effects of these defects on mechanical properties of single-walled carbon nanotubes (SWCNTs). MD simulation has also been used to study the effect of variation of radius of defective CNTs on their elastic moduli. Results have also been obtained for defective SWCNT/polypropylene composites. Results show that a gradual degradation of elastic moduli is observed with increasing diameter and the number of defects of armchair CNTs. As the number of defects increases, the moduli of CNTs with SW defects decreases more rapidly in comparison to the decrease in moduli for CNTs with vacancy defects. Percentage increase in different moduli with increase in CNT volume fraction is greater for CNTs with vacancy defects in comparison to CNTs with SW defects.

Research on the Elastic Modulus of Single-Walled Carbon Nanotubes

The calculation of elastic modulus of carbon nanotubes is an essential prerequisite for future Micro-nano devices fabrication that based on carbon nanotubes. The interaction potential of C-C covalent bond in single-walled carbon nanotubes (SWCNTs) is described by Terrsoff-Brenner potential in this paper. The elastic modulus of SWCNTs is ranged from 1.1078TPa to 1.23789TPa with the diameter increases from 0.3176nm to 2.0626nm by molecular dynamics (MD) simulation. The critical diameters of armchair and zigzag nanotubes are 1nm and 0.6nm.The elastic modulus changes with the diameter of nanotubes increasing clearly when the diameter smaller than the critical diameter, but the value of elastic modules tends to convergence when the diameter of nanotubes larger than the critical diameter.