The dynamics of spreading of miroscopic nonvolatile polymer droplets on surfaces has been studied by the molecular-dynamics method. Simulations have been performed for mixtures of solvent and dimer, solvent and tetramer, and solvent and octamer droplets. For solvent particles and dimers, the dynamical layering is characteristic, with stepped droplet shapes. However, for tetramers and octamers a tendency for layering is evident for relatively deep and strong surface potentials only, with one layer developing. For wider and more shallow potentials more rapid spreading and rounded droplet shapes occur, due to mixing of the layers. These results suggest that the molecular structure of the liquid may play a role in determining different experimentally seen density profiles of nonvolatile droplets.

• Received 7 December 1993

DOI:https://doi.org/10.1103/PhysRevE.49.4228