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. 2016 Aug 24:6:31837.
doi: 10.1038/srep31837.

Lubricity of gold nanocrystals on graphene measured using quartz crystal microbalance

M S Lodge  1 , C Tang  2 , B T Blue  1 , W A Hubbard  3 , A Martini  2 , B D Dawson  1 , M Ishigami  1
Affiliations

Lubricity of gold nanocrystals on graphene measured using quartz crystal microbalance

M S Lodge et al. Sci Rep. .

Abstract

In order to test recently predicted ballistic nanofriction (ultra-low drag and enhanced lubricity) of gold nanocrystals on graphite at high surface speeds, we use the quartz microbalance technique to measure the impact of deposition of gold nanocrystals on graphene. We analyze our measurements of changes in frequency and dissipation induced by nanocrystals using a framework developed for friction of adatoms on various surfaces. We find the lubricity of gold nanocrystals on graphene to be even higher than that predicted for the ballistic nanofriction, confirming the enhanced lubricity predicted at high surface speeds. Our complementary molecular dynamics simulations indicate that such high lubricity is due to the interaction strength between gold nanocrystals and graphene being lower than previously assumed for gold nanocrystals and graphite.

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Figures

Figure 1
Figure 1
(a) AFM image of gold nanocrystals on the QCM with graphene. (b) High resolution transmission electron microscopy image of a representative single gold nanocrystal on graphene. (Inset) Diffraction pattern of the nanocrystal showing the fcc crystal structure.
Figure 2
Figure 2
(top) Changes in the dissipation of the control and graphene QCM during gold evaporation. (bottom) The frequency shifts of the control and graphene QCM are plotted as functions of time during gold deposition. The slight fluctuation in the frequency and the dissipation observed prior the opening of the shutter is due to the sensitivity of the QCMs to the radiative heating induced by the evaporator.
Figure 3
Figure 3
(a) Frequency shift, (b) change in dissipation, and (c) slip time as a function of the oscillation amplitude of the graphene QCM.
Figure 4
Figure 4. Calculated drag coefficient as a function of the interaction strength between graphene and gold nanocrystals with 3.3 and 4.5 nm diameters; inset is a snapshot of the simulation.
Dashed lines indicate the range of the drag coefficients determined from the measured slip time.
See this image and copyright information in PMC

References

    1. Muser M. H. Structural lubricity: Role of dimension and symmetry. Europhysics Letters, 66, 97–103 (2004).
    1. Sacco J. E. & Sokoloff J. B. Free sliding in lattices with two incommensurate periodicities. Physical Review B, 18, 6549 (1978).
    1. Sokoloff J. B. Theory of energy dissipation in sliding crystal surfaces. Physical Review B, 42, 760 (1990). - PubMed
    1. Hirano M., Shinjo K., Kaneko R. & Murata Y. Anisotropy of frictional forces in muscovite mica. Physical Review Letters, 67, 2642 (1991). - PubMed
    1. Liu Z. et al.. Observation of Microscale Superlubricity in Graphite. Physical Review Letters, 108, 205503 (2012). - PubMed

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