Retraction and bouncing dynamics of nanodroplets upon impact on superhydrophobic surfaces

This work investigates the retraction and bouncing dynamics of an impacting low-viscosity nanodroplet on superhydrophobic surfaces via molecular simulations, aiming to reveal scaling laws velocities establish relationship between them. The velocity, Vre, is found scale as Vre ∼ Dmax/τc,n, where Dmax maximum spreading diameter, τc,n = (D0/V0)We1/2Oh1/3 inertial-capillary-viscous time, We Oh are Weber number Ohnesorge number, respectively. stems from collision retracting rim at center nanodroplet, leading velocity velocity. Combining Dmax/τc,n with law We1/2Oh1/3D0 yields both impact indicating that nanodroplets a surface depend merely An energy analysis shows proportion state (Es,max) initial kinetic (Ek,ini) follows Es,max/Ek,ini Oh2/3, whereas (Ek,b) Ek,b/Es,max Oh−2/3, constant Ek,b/Ek,ini also restitution coefficient for surfaces.