  The spreading of liquid nanodroplets of different initial radii $R_{0}$ is
studied using molecular dynamics simulation. Results for two distinct systems,
Pb on Cu(111), which is non-wetting, and a coarse grained polymer model, which
wets the surface, are presented for Pb droplets ranging in size from $\sim55
000$ to $220 000$ atoms and polymer droplets ranging in size from $\sim200 000$
to $780 000$ monomers. In both cases, a precursor foot precedes the spreading
of the main droplet. This precursor foot spreads as $r_{f}^{2}(t)=2D_{eff}t$
with an effective diffusion constant that exhibits a droplet size dependence
$D_{eff}\sim R_{0}^{1/2}$. The radius of the main droplet $r_{b}(t)\sim
R_{0}^{4/5}$ in agreement with kinetic models for the cylindrical geometry
studied.
