ABSTRACT
Abstract In this theoretical study, the work done on a sessile drop during spreading was estimated. It was found that the energy required to stretch the contact line is much greater than the energy needed to stretch the airliquid interfacial area. The model shows that wetting energies are relatively small for large contact angles, but increase dramatically as contact angles tend towards zero. For a given drop volume, more work is needed to spread higher surface tension liquids than lower surface tension ones. Similarly, larger drops require more energy to spread than smaller ones. The work of wetting estimated here for sessile drops is comparable to energies from other wetting geometries, such as capillary bridge and sphere tensiometry. This work provides theoretical support for the experimental observation that interactions at the contact line dominate the wetting behavior of spreading sessile drops.
