Origami theory-inspired multiscale simulation of folded graphene aerogel with improved mechanical properties

In our previous work, inspired by the Origami theory, folded graphene oxide aerogel (fGA) with the arch morphology was successfully prepared. However, the self-folding mechanism of folded graphene oxide (fGO) and the enhancement mechanism of the interlayer interface were hard to be explained. Therefore, building on previous work, this study adopted a multiscale modeling approach. By using the molecular dynamics (MD) method, the folding mechanism of fGO was investigated on a microscopic scale. The effect of fGO microstructure on mechanical properties was also studied. GO folding was attributed to Cu2+ coordination and electrostatic interactions. Compared to GO, fGO showed better mechanical property parameters. Furthermore, the mechanical behavior of the samples was researched on a macroscopic scale. The connection points between the sheet layers increased and became tighter when the fGA structure was stressed. The strength and resistance to deformation of the aerogel became strong and stabilized the structure. The interfacial bonds were mainly enhanced in the interlayer by the increase of hydrogen bonding (H bond) and van der Waals forces (vdW). Thus, the multiscale modeling approach was of theoretical guidance for the improvement of the mechanical properties of fGA.