Design and analysis of sandwiched fullerene-graphene composites using molecular dynamics simulations

Computational design of a novel carbon based hybrid material that is composed of fullerene units covalently sandwiched between parallel graphene sheets is presented. In this regard, atomistic models for the proposed novel material structure are generated via a systematic approach by employing different fullerene types (i.e. C180, C320, C540 and C720) as sandwich cores. Then, thermodynamic stability of the atomistic structures is checked by monitoring free energy profiles and junctional bond configurations which are obtained through classical molecular dynamics (MD) simulations. Thermodynamic feasibility of all atomistic specimens with different fullerene types is suggested by the energy profiles, because total configuration energies for all systems are minimized and remained stable over a long period of time. Furthermore, mechanical behavior of the nano-sandwiched material system is investigated by performing compression tests via MD simulations and basic deformation mechanisms underlying the compressive response are determined. By detailed examination, it is shown that proposed nano-sandwiched material can be identified as quasi-foam material due to comparable energy absorbing characteristics. Furthermore, regarding the effect of fullerene size on the compressive response, it is found that for a given stress level, specimens with larger fullerenes exhibit higher energy absorbing capacity.