Mechanical characterization of vacancy defective single-walled carbon nanotube/epoxy composites

Abstract

A pristine Carbon nanotube (CNTs) possesses outstanding mechanical properties. However, the performance of CNTs get affected from defects such as vacancies, Stone-Wales (S-W), hybridization and doping which can appear during production.The study conducted here is based on molecular dynamics (MD) simulations performed on vacancy defected single-walled carbon nanotubes (SWCNTs) and their corresponding epoxy composites. A (6, 6) armchair SWCNT has been used in this study with the defect ratio (DR) varies from 1 to 5.0%. Three different vacancies pattern such as symmetric, asymmetric and mixed in SWCNTs are modeled and simulated for obtaining the mechanical properties. Results have also been obtained for defective SWCNT/epoxy composites. Results show that a gradual degradation of Young’s moduli of both SWCNT and their composite with increasing DR. As the DR increases, the moduli of mixed defect pattern SWCNT and its corresponding composites decreases more rapidly in comparison to the decrease in moduli for other vacancy patterns and their composites. Maximum reduction of 14.5% in failure strain has been noticed in mixed vacancy pattern for 5.0% DR compare to pristine SWCNTs.A maximum degradation of 20% has also been noticed in moduli of the composite made by the reinforcement of mixed vacancy pattern compare to pristine SWCNT/epoxy composite. Therefore, comparative approach of this study leads to more reliable design of epoxy nanocomposites.