Droplet spreading driven by van der Waals force: a molecular dynamics study
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AbstractThe dynamics of droplet spreading is investigated by molecular dynamics simulations for two immiscible fluids of equal density and viscosity. All the molecular interactions are modeled by truncated Lennard-Jones potentials and a long-range van der Waals force is introduced to act on the wetting fluid. By gradually increasing the coupling constant in the attractive van der Waals interaction between the wetting fluid and the substrate, we observe a transition in the initial stage of spreading. There exists a critical value of the coupling constant, above which the spreading is pioneered by a precursor film. In particular, the dynamically determined critical value quantitatively agrees with that determined by the energy criterion that the spreading coefficient equals zero. The latter separates partial wetting from complete wetting. In the regime of complete wetting, the radius of the spreading droplet varies with time as R(t) ∼ √t, a behavior also found in molecular dynamics simulations where the wetting dynamics is driven by the short-range Lennard-Jones interaction between liquid and solid. © 2010 IOP Publishing Ltd.
CitationWu C, Qian T, Sheng P (2010) Droplet spreading driven by van der Waals force: a molecular dynamics study. J Phys: Condens Matter 22: 325101. Available: http://dx.doi.org/10.1088/0953-8984/22/32/325101.
SponsorsThis publication was based on work supported in part by award no. SA-C0040/UK-C0016, made by the King Abdullah University of Science and Technology (KAUST), Hong Kong RGC grant no. 602007 and the Croucher Foundation grant Z0138. We would like to thank Yana Di and Xiao-Ping Wang for helpful discussions.
CollectionsPublications Acknowledging KAUST Support
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