Mercury Droplet Formation on a Graphene Surface. Computer Experiment

Colloid Journal, 2015, Vol. 77, No. 5, pp. 582–591. © Pleiades Publishing, Ltd., 2015.

Original Russian Text © A.E. Galashev, 2015, published in Kolloidnyi Zhurnal, 2015, Vol. 77, No. 5, pp. 593–602.

A. E. Galashev

Abstract—Molecular dynamics method has been employed to study rapid heating of a mercury film ongraphene containing Stone–Wales defects. Hydrogenated edges of a graphene sheet withstand heating by 800 K. As the film contracts into a droplet, the horizontal component of the self-diffusion coefficient of Hg atoms monotonically decreases, while the vertical component passes through a deep minimum, which reflects the onset of droplet rising over the substrate. Droplet formation manifests itself as upward widening of the vertical density profile and an increase in the number of peaks in it. Therewith, the length of the radial distribution function of mercury substantially diminishes and the intensity of its first peak increases. Formation of the droplet leads to a decrease in the blunt contact angle. Temperature-related changes in graphene manifest themselves as a rise in the intensity of additional peaks in the angular distribution of the closest neighbors, oscillatory pattern of the stresses acting in its plane, and an almost linear growth of roughness.

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