Dynamics of a Complete Wetting Liquid Under Evaporation

We describe a simple model of a contact line under purely diffusive evaporation and complete wetting condition taking into account the divergent nature of evaporative flux near the contact line as proposed by Deegan et al. [Nature 389:827, 1997] by using electrostatic analogy. We show the existence of a precursor film at the edge of the liquid and generalize Tanner’s law accounting for evaporative effects. We apply this model to the problem of evaporation of a liquid droplet and partly recover the dynamics of spreading and retraction found in experiments [Poulard et al., Langmuir 21:8226–8233, 2005].