Effect of reconstructed vacancy defects on the crumpling behavior of graphene sheets

Abstract

Understanding the influence of reconstructed single vacancy (SV) defects on the crumpling behavior of graphene sheets is crucial for successful implementation of graphene in advanced technologies. Here, we report the results of a systematic coarse-grained molecular dynamics (CG-MD) simulation study of the crumpling process of graphene sheets at varying degree of reconstructed SV defects. We find that two-dimensional (2D) defective graphene sheets with larger degree of SV defects reconstruction exhibit more wrinkling in equilibrium than pristine graphene and less reconstructed defective sheets. By evaluating the evolution of potential energy of the sheet during the crumpling process, our results show that the reconstructed SV defects reduce the adhesion properties while greatly increase the angle potential energy. Moreover, the shape descriptor analysis shows less self-folding and self-adhering upon crumpling for sheets with larger degree of defects reconstruction. The analyses of the sheet pressure and bulk modulus indicate that the larger the degree of defects reconstruction, the more difficult it is to compact the sheet into a crumple, corresponding to a greater bulk modulus. The evaluation of stress distribution of the sheet further reveals the stress heterogeneity arising from defects and crumpling. Our findings highlight the critical role of reconstructed SV defects in the crumpling process of graphene sheets, which has significant implications for the tailored design of crumpled defective materials.

Keywords

• Coarse-grained modeling
• Molecular dynamics
• Crumpled graphene sheet
• Single vacancy defect
• Reconstructed vacancy defect