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Slippery and Wear-Resistant Surfaces Enabled by Interface Engineered Graphene

2019; American Chemical Society; Volume: 20; Issue: 2 Linguagem: Inglês

10.1021/acs.nanolett.9b03650

1530-6992

Neeraj Dwivedi, Tarak K. Patra, Jae-Bok Lee, Reuben J. Yeo, Srilok Srinivasan, Tanmay Dutta, Kiran Sasikumar, Chetna Dhand, S. Tripathy, Mohammad S. M. Saifullah, Aaron J. Danner, S. A. R. Hashmi, Avanish Kumar Srivastava, Jong‐Hyun Ahn, Subramanian K. R. S. Sankaranarayanan, Hyunsoo Yang, Charanjit S. Bhatia,

Graphene and Nanomaterials Applications

Friction and wear remain the primary cause of mechanical energy dissipation and system failure. Recent studies reveal graphene as a powerful solid lubricant to combat friction and wear. Most of these studies have focused on nanoscale tribology and have been limited to a few specific surfaces. Here, we uncover many unknown aspects of graphene's contact-sliding at micro- and macroscopic tribo-scales over a broader range of surfaces. We discover that graphene's performance reduces for surfaces with increasing roughness. To overcome this, we introduce a new type of graphene/silicon nitride (SiNx, 3 nm) bilayer overcoats that exhibit superior performance compared to native graphene sheets (mono and bilayer), that is, display the lowest microscale friction and wear on a range of tribologically poor flat surfaces. More importantly, two-layer graphene/SiNx bilayer lubricant (<4 nm in total thickness) shows the highest macroscale wear durability on tape-head (topologically variant surface) that exceeds most previous thicker (∼7–100 nm) overcoats. Detailed nanoscale characterization and atomistic simulations explain the origin of the reduced friction and wear arising from these nanoscale coatings. Overall, this study demonstrates that engineered graphene-based coatings can outperform conventional coatings in a number of technologies.