Comparison of frictional forces on graphene and graphite

Abstract

We report on the frictional force between an SiN tip and graphene/graphite surfaces using lateral force microscopy. The cantilever we have used was made of an SiN membrane and has a low stiffness of 0.006 N m(-1). We prepared graphene flakes on a Si wafer covered with silicon oxides. The frictional force on graphene was smaller than that on the Si oxide and larger than that on graphite (multilayer of graphene). Force spectroscopy was also employed to study the van der Waals force between the graphene and the tip. Judging that the van der Waals force was also in graphite-graphene-silicon oxide order, the friction is suspected to be related to the van der Waals interactions. As the normal force acting on the surface was much weaker than the attractive force, such as the van der Waals force, the friction was independent of the normal force strength. The velocity dependency of the friction showed a logarithmic behavior which was attributed to the thermally activated stick-slip effect.

Superlubricity in Layered Nanostructures

“…On the other hand, the corrugation strength is significantly decreased when the number of graphene layers in Ni-graphene-Ni structures are increased. This trend is seemingly in accordance with experimental observations [44,46]. However, as mentioned above, the system at hand is very different from those considered in the experiments and the trends revealed by Fig.…”

“…Recently, several experimental works investigated the variation in friction force when the number of 2D layers are varied from single layer to many layers representing the bulk structure [44][45][46]. Lee et al used friction force microscope with a SiN tip to investigate atomic friction on graphite and graphene flake prepared on silicon oxide layer [44].…”

“…Lee et al used friction force microscope with a SiN tip to investigate atomic friction on graphite and graphene flake prepared on silicon oxide layer [44]. They have found that friction on graphene was lower than on silicon oxide but higher than that on graphite.…”

Preparation of surface coatings on a conductive substrate by controlled motion of graphene nanoflakes in a liquid medium

“…Here, it must be noted that the graphene oxide nanosheets (e.g. the defects near the anode) can also be a good corrosion-inhibiting coating with a superfine abrasion performance, as reported in the previous studies [1][2][3][4]20]. 8 In general, it requires at least 10 kV high voltage to drive the large-sized particles (>200 μm) to move on an insulator substrate [12,13].…”

“…Accordingly, increasing attention has been paid to develop new materials, coatings, and lubricants that can potentially provide low friction and wear even under severe operating conditions [1][2][3]. Graphene, a two-dimensional carbon materials, was only very recently explored that it had unusual properties to reduce wear and friction in nano-scale to macro-scale systems due to the interplay of surface traction forces [4] and the effect of electron-phonon coupling [5]. Considering the fact that most of the previous studies have concentrated on the nano-scale friction [6,7], this is of particular interest in probing the tribological behaviors of graphene at a large scale for expanded practical applications.…”