(723i) On the Requirements for the Formation and Shape of Precursors in Droplet Spreading

We study the requirements for the formation and shape of precursors using molecular dynamics simulations. Using a new method for analyzing our spreading simulations, we identify three regimes with increasing substrate energy: no precursor, a monolayer precursor, and a continuously growing precursor. Changes in free energy of layer formation are reported for the first time and explain the onset and the different types of precursors. Our results also resolve the contradicting claims regarding the role of the spreading coefficient as a requirement for precursor formation.