| AVS 66th International Symposium & Exhibition | |
| Advanced Surface Engineering Division | Friday Sessions |
| Session SE+AS+SS-FrM |
| Session: | Tribology: From Nano to Macro-scale |
| Presenter: | Prathima Nalam, University at Buffalo, State University of New York |
| Authors: | P. Nalam, University at Buffalo, State University of New York B. Sattari Baboukani, University at Buffalo, State University of New York Z. Ye, Miami University |
| Correspondent: | Click to Email |
Two-dimensional (2D) materials such as graphene, etc. are emerging as friction-reducing additives for transmission fluids and lubricating oils to enhance the service life of sliding metallic components. Here in this work, we investigate the dissipative mechanism for a supported (on silica substrate), monolayer of graphene when immersed in organic solvents such as n-hexadecane and cyclohexane. Nanoscale friction measurements on graphene conducted using atomic force microscope showed a non-monotonic variation i.e. a decrease and then an increase in friction forces as a function of immersion time in organic solvents. This behavior was attributed to the re-arrangement of organic molecules at the 2D confinement formed between the graphene and the underlying substrate. The oscillatory forces measured at the interface showed an increased packing order of the solvent molecules under 2D confinement and with equilibration time lead to a higher dissipative interface. The diffusion of organic molecules to the 2D confinement also results in a partially-suspended graphene layer and the interfacial friction is discussed by understanding the quality (local pinning states of individual atoms) of the contact made by the AFM probe while sliding on graphene.