Large scale molecular dynamics simulations for bidisperse nanoparticle suspensions with an explicit solvent are used to investigate the effects of evaporation rates and volume fractions on the nanoparticle distribution during drying. Our results show that “small-on-top” stratification can occur when Pe

_{s}Φ_{s}≳ c with c ~1, where Pe_{s}is the Péclet number and Φ_{s}is the volume fraction of the smaller particles. This threshold of Pe_{s}Φ_{s}for “small-on-top” is larger by a factor of ~α^{2}than the prediction of the model treating solvent as an implicit viscous background, where α is the sizemore »