▎ 摘 要
Interface bonding is crucial in fabricating graphene/copper composite because of immiscibility and poor wettability of C-Cu and weak force between graphene layers. Meanwhile, it is challenging to quantitatively evaluate the bonding strength of graphene-included interface. Here, bonding at multilayer graphene-copper interface is effectively manipulated by graphene functionalization via plasma treatments on graphene/copper foils before they are stacked and consolidated to composite, and a quantitative method is proposed for evaluating the bonding strength by tensile testing on bulk specimens with single interfaces across the whole section. The experimental results indicate that oxygen plasma functionalization is more effective in improving the interface bonding, by which a strength of at least 154 MPa comparable to the tensile strength of pure copper is achieved with the layer number of graphene even up to ~30. The enhancement mechanisms for the interface bonding strength are also discussed based on the microstructure analysis and molecular dynamics simulations.