Effect of graphene concentration on tribological properties of graphene aerogel/TiO2 composite through controllable cellular-structure

The microstructure design of the packing is a crucial factor in determining the performances of sealing capacity. Graphene aerogel/TiO2 (GA/TiO2) composites were fabricated by an infiltration method using porous GA as a framework. GA with different pore sizes and morphologies was tuned by changing concentration of graphene. The structural morphology of the graphene layer structure transformed into porous structure as the graphene concentrations increased. In addition, mechanical properties and tribological behaviors of GA/TiO2 composites with different graphene concentrations were comparatively investigated. The results show that the TiO2 particles are more uniformly filled into the GA with higher graphene concentration due to the porous separation effect. Therefore, the GA/TiO2 composites of higher concentrations have a better elongation and mechanical properties. Simultaneously, the tribological behavior is excellent owing to the self-lubricating properties of graphene and tiny TiO2, and the TiO2 cluster can effectively prevent the crack propagation. Moreover, the tribological performance of the GA/TiO2 samples under wet friction conditions is better than that under dry friction conditions due to the self-transport operation of lubricants assisted by the through capillary action, besides the self-lubricating effect of graphene and tiny TiO2 particles.