Mechanical abnormality in graphene-based lamellar superstructures

Graphene aerogels and foams have gained widespread interest due to their impressive mechanical properties as well as their ability to be tuned for optimal performance in a variety of applications. It is highly desirable to attain theoretical relationships to help predict their behavior. Here we employ molecular dynamics simulation to explore the behavior of a graphene aerogel-inspired superstructure under applied compression and tension with a focus on the mechanical stabilizing mechanisms and properties of the deformed structures. The biomimetic structure consists of lamellae and equally spaced bridges, which allows the structure to be lightweight, strong, and resilient. Our results show that the material is highly anisotropic in both tension and compression. In compression, the material is compressible with no permanent loss of structure 75% strain with ultimate strengths on the order of 100 GPa. In tension, the material is elastic up to 26% strain in one direction and up to 84% in the other, with ultimate strengths of between 2 and 30 GPa in one direction and 78 GPa in the other. The material is also shown to possess unusual lateral strain responses in tension and compression which are dependent on bridge length.