Molecular simulation study of the adhesion work for water droplets on water monolayer at room temperature

The wetting phenomenon of water droplets coexisting with the ordered water monolayer termed an unexpected phenomenon of “water that does not wet a water monolayer” at room temperature has been found on several solid surfaces. Although the hydrogen bond saturation inside the monolayer can qualitatively describe this phenomenon, whether the Young-Dupré equation still holds under this unconventional wetting framework is still not answered. In this work, we have calculated the contact angle values of the droplets as well as the work of adhesion between the droplets and the monolayer based on an extended phantom-wall method. The results show that similar to the conventional solid-liquid interface, classical Young-Dupré equation is also applicable for the interface of liquid water and ordered water monolayer.