Study of Viscoelastic Properties of Graphene Foams Using Dynamic Mechanical Analysis and Coarse-Grained Molecular Dynamics Simulations

As a promising nano-porous material for energy dissipation, the viscoelastic properties of three-dimensional (3D) graphene foams (GrFs) are investigated by combining a dynamic mechanical analysis (DMA) and coarse-grained molecular dynamic (CGMD) simulations. The effects of the different factors, such as the density of the GrFs, temperature, loading frequency, oscillatory amplitude, the pre-strain on the storage and loss modulus of the GrFs as well as the micro-mechanical mechanisms are mainly focused upon. Not only the storage modulus but also the loss modulus are found to be independent of the temperature and the frequency. The storage modulus can be weakened slightly by bond-breaking with an increasing loading amplitude. Furthermore, the tensile/compressive pre-strain and density of the GrFs can be used to effectively tune the viscoelastic properties of the GrFs. These results should be helpful not only for understanding the mechanical mechanism of GrFs but also for optimal designs of advanced damping materials.

Automated summary

The viscoelastic properties of three-dimensional graphene foams (GrFs) are investigated using a combination of dynamic mechanical analysis (DMA) and coarse-grained molecular dynamics (CGMD) simulations. The effects of factors such as GrFs density, temperature, loading frequency, oscillatory amplitude, and pre-strain on the storage and loss modulus are studied. The results show that both the storage and loss modulus are independent of temperature and frequency, and the storage modulus can be slightly weakened by increasing the loading amplitude. Furthermore, the viscoelastic properties of GrFs can be effectively tuned by the tensile/compressive pre-strain and density.