Graphene aerogel: deformation behaviour from molecular dynamics

Abstract

Graphene aerogels or honeycomb structures are a promising new class of materials with intriguing properties. Aerogels are highly porous solid foams that have an interconnected network of thin but strong graphene walls.
The mechanical properties of graphene aerogels are of great importance for electronics, nanomechanical devices, and the creation of new composites. These aerogels demonstrate high strength, but the deformation of such porous frameworks is quite unusual. These structures are also superelastic and highly compressible. To improve the mechanical properties of graphene aerogels, supporting elements such as graphene flakes, which appeared during the synthesis of graphene aerogels, nanotubes, or metal nanoparticles can be added to the pores. In this work, the mechanical properties of three different morphologies of graphene aerogel under tension were studied using molecular dynamics. The tensile strength along different lattice directions was studied and analyzed.
It was found that the strength depends significantly on the morphology of the structure and the loading direction. In the first stage of deformation, no increase in stresses is observed due to the changes of the pore shape. Then, the stresses are concentrated at the joints of the honeycomb structure and along the walls. The addition of carbon nanotubes and graphene flakes to the cells of the graphene aerogel does not increase the strength. The obtained results contribute to the understanding of the mechanisms of microscopic deformation of graphene aerogels and their design for various applications.

Speaker

Julia A. Baimova
Institute for Metals Superplasticity Problems of RAS
Russia

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