Robust Superlubricity of Gold–Graphite Heterointerfaces

Rotem, Yaniv; Koren, Elad

doi:10.1002/adfm.201901138

Cited by 18 publications

(13 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The raw friction data from the simulations with pentanol and phenol at the 10 nN load are shown in Figure S1a,b and illustrate the larger force fluctuations for phenol, particularly after about 2 nm of sliding. It has been previously proposed that the STDEV of the lateral force can be used as a measure of frictional energy dissipation . Therefore, both mean and standard deviation of the force are relevant to the comparison between phenol and pentanol; as shown in Figure , both are larger for phenol in experiments and simulations.…”

Section: Resultsmentioning

confidence: 94%

See 1 more Smart Citation

Effect of Ambient Chemistry on Friction at the Basal Plane of Graphite

Khajeh

Chen

Kim

et al. 2019

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

Graphite is widely used as a solid lubricant due to its layered structure which enables ultra-low friction. However, the lubricity of graphite is affected by ambient conditions and previous studies have shown a sharp contrast between frictional behavior in vacuum or dry environments compared to humid air. Here we studied the effect of organic gaseous species in the environment, specifically comparing the adsorption of phenol and pentanol vapor. Atomic force microscopy experiments and reactive molecular dynamics simulations showed that friction was larger with phenol than pentanol. The simulation results were analyzed to test multiple hypotheses to explain the friction difference and it was found that mechanical force-driven chemical bonding between the tip and phenol molecules plays a critical role. Bonding increases the number of phenol molecules in the contact which increases adhesion as well as the number of atoms in registry with the topmost graphene layer that act as pinning sites to resist sliding. The findings of this research provide insight into how the chemistry of the operating environment can affect the frictional behavior of graphite and layered materials more generally.

show abstract

Section: Resultsmentioning

confidence: 94%

“…It has been previously proposed that the STDEV of the lateral force can be used as a measure of frictional energy dissipation. 46 Therefore, both mean and standard deviation of the force are relevant to the comparison between phenol and pentanol; as shown in Figure 2, both are larger for phenol in experiments and simulations.…”

Section: ■ Results and Discussionmentioning

confidence: 98%

Effect of Ambient Chemistry on Friction at the Basal Plane of Graphite

Khajeh

Chen

Kim

et al. 2019

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

show abstract

“…4. We note that the CE is of the order of 0.075 meV per C-atom, indicating an exceptionally lubric contact [22]. We would like to note that we obtain CE and AE values using energy differences of nearly identical systems, thus we expect a very high numerical accuracy.…”

Section: A Graphene On Goldmentioning

confidence: 78%

“…Extended contacts, on the other hand, were predicted to prefer intermediate misfit angles 0 < θ < 30 • [21]. This, in turn, is expected to be manifested in the interfacial tribological properties, where the combination of the weak Au-C interactions and the strong internal cohesive forces of gold and graphene may lead to exceptionally low friction coefficients (<10 −3 ) -a condition often referred to as structural superlubricity [6,22,23]. In superlubric systems the corrugation energy (CE) -the energy barrier resisting sliding -can decrease to values much below the meV per interface atom.…”

Section: Introductionmentioning

confidence: 99%

Registry dependent potential for interfaces of gold with graphitic systems

Ouyang¹,

Hod²,

Guerra³

2021

Preprint

View full text Add to dashboard Cite

We present a semi-anisotropic interfacial potential (SAIP) designed to classically describe the interaction between gold and two-dimensional (2D) carbon allotropes such as graphene, fullerenes, or hydrocarbon molecules. The potential is able to accurately reproduce dispersion corrected density functional theory (DFT+D3) calculations performed over selected configurations: a flat graphene sheet, a benzene molecule, and a C60 fullerene, physisorbed on the Au(111) surface. The effects of bending and of hydrogen passivation on the potential terms are discussed. The presented SAIP potential provides a noticeable improvement in the state-of-the-art description of Au-C interfaces. Also, its functional form is suitable to describe the interfacial interaction between other 2D and bulk materials.

show abstract

“…Coefficients of friction of µ < 0.1 were shown for thermoplastic TEHL contacts. Hence, coefficients of friction in the range of superlubricity are possible [13][14][15]. Vicente et al [7] and Persson and Scaraggi [16] point out that both rolling and sliding fluid friction have to be considered in thermoplastic TEHL contacts.…”

Section: Introductionmentioning

confidence: 99%

Friction and Temperature Behavior of Lubricated Thermoplastic Polymer Contacts

et al. 2020

View full text Add to dashboard Cite

This work focuses on the friction and temperature behavior of thermo-elastohydrodynamically lubricated (TEHL) contacts under rolling-sliding conditions. For this purpose, a twin-disk test rig is used with a hybrid setup of plain and fiber-reinforced polyamide (PA) 66 and polyetheretherketone (PEEK) disks paired with case-hardened steel disks and three different lubricants. Experimental investigations include various lubrication regimes by varying sum velocity and oil temperature as well as load and slip ratio. The measured friction in thermoplastic TEHL contacts is particularly very low in the area of high fluid load portion, which refers to the large deformation of the compliant polymer surface. Newtonian flow behavior mainly determines fluid friction. The low thermal effusivity of polymers insulates the contact and can further reduce the effective lubricant viscosity, and thus the fluid friction. For low sum velocities, solid friction influences the tribological behavior depending on the solid load portion. Although the interfacial contact friction is comparably small, material damping strongly contributes to power losses and increases bulk temperature, which in turn affects the TEHL contact. Thus, loading frequency and the resulting bulk temperature are identified as one of the main drivers of power losses and tribological behavior of lubricated thermoplastic polymer contacts.

show abstract

Robust Superlubricity of Gold–Graphite Heterointerfaces

Cited by 18 publications

References 29 publications

Effect of Ambient Chemistry on Friction at the Basal Plane of Graphite

Effect of Ambient Chemistry on Friction at the Basal Plane of Graphite

Registry dependent potential for interfaces of gold with graphitic systems

Friction and Temperature Behavior of Lubricated Thermoplastic Polymer Contacts

Contact Info

Product

Resources

About