(192ak) Molecular Simulation of Mechanical Properties of Multilayer Graphene Oxide Nanosheets

Multilayer Graphene Oxide Nanosheets

Xu Zhang, Xiaoning Yang*

College of Chemical Engineering, Nanjing Tech University

Nanjing 210009, China

 

ABSTRACT: Multilayer graphene oxide nanostructure is an attractive candidate for new applications in nanoelectromechanical material and structural reinforcement nanocomposites. The mechanical properties of multilayer graphene oxide (GO) nanosheet play a pivotal role which connects the monolayer and bulk graphene oxide. In this study, the mechanical properties and failure mechanism of multilayer GO structure were examined by molecular dynamics simulation. Under uniaxial loading along the armchair direction, the Young’s modulus of multilayer GO nanosheets was found to slowly decrease with the increase of the number of GO layer. During mechanical failure, the failure of each GO layer in multilayer GO nanosheets was asynchronous. The function groups of GO largely affect the fracture of GO sheets. The fracture of the external GO layer begins with the breaking of the bonds associated with hydroxyl-functionalized carbon atoms and a transformation from epoxide to ether groups. The fracture energy of the external GO layer can be transferred though interlayer hydrogen bond network within the gallery space of the GO nanosheets, which causes the larger Young’s modulus and failure strain of the middle layer than the external layers. These simulation results are expected to bridge the understanding of significant different mechanical behavior between monolayer and multilayer GO nanosheets and can be useful for engineering thickness of GO with tunable mechanical properties.

 

ACKNOWLEDGMENTS

This work was supported by the National Natural Science Foundation of China under Grants 21376116