Dynamics of wetting and spreading: A numerical study

We present results from a detailed numerical study of a Langevin model proposed by Abraham et al. [Phys. Rev. Lett. 65, 195 (1990)] for spreading and wetting of a liquid drop. In the partially wet case, we find that the system relaxes to a stable wetting angle. On the other hand, for the case of complete wetting, we find a precursor film advancing linearly with time and with a well-defined speed given in terms of the parameters of the above-mentioned model. We have also studied the possibility of a layering of the precursor film in the presence of longer-range interactions with the substrate. All our results are in excellent agreement with theoretical predictions based on the model.