Investigation of Young's modulus of defective graphene-reinforced epoxy at different weight ratios by molecular dynamics

Abstract

Experimental studies have shown that adding graphene to epoxy at even a low weight ratio increases strength, temperature resistance, and electrical conductivity. This study examines the effects of combining graphene with epoxy and assesses Young's modulus of the resulting nano-composite materials with various defective graphene types. Molecular dynamics (MD) simulation is are utilized to predict the mechanical properties of nano-composite materials, and a heuristic protocol is implemented to avoid incorrect bond structures during crosslinking reactions. The study demonstrates that adding graphene to epoxy increases Young's modulus, but the effect declines when the graphene is defective. These results significantly advance the field's knowledge by providing a new understanding of the effects of pristine and defective graphene reinforcement on epoxy Young's modulus. This research stands out for its evaluation of the impact of various graphene defects on epoxy properties using MD simulations. The employed heuristic protocol in this study, which includes thorough updates of both bonded and non-bonded terms as well as partial charges, serves as a more reliable algorithm than iterative multi-step protocols by reducing the risk of incorrect molecular linkages resulting from the neglect of angle-based covalent terms. Additionally, this study evaluates the constant strain minimization method's suitability for determining the mechanical properties of nano-composite materials. Finally, a thorough comparison between the simulation results and the existing experimental findings reported in scholarly sources was made to guarantee the full disclosure of both qualitative and quantitative results within the scope of the investigation.