Coarse-Grained Modeling of the Water/Alkane Wetting and Dewetting Processes on Fluorinated Coatings

This work provides a framework to digitally assess any droplet's static and dynamic contact angles on coatings and polymeric substrates. We are introducing a new dissipative particle dynamics coarse-grained model to attain the spatiotemporal conditions and the coexistence of different phases that such investigation dictates. Two computational techniques are additionally developed; a robust technique to calculate the static contact angle using density profiles and a perturbation method to evaluate dynamic contact angles. A parallel force to the surface force is applied to emulate the receding and advancing dynamics. We have validated our protocols for the static contact angle of water for a series of polymeric surfaces and the dynamic contact angle for three different fluorinated additives. We reproduced the correct hysteresis trends between the droplet content and the surface. The fluorinated nature of the additive's tails is the driving force of directed self-assembly and, consequently, the repelling nature of the surface. An equally important factor for designating the interaction profile of the surface is the coating's chemical structure, which is responsible for inhibiting or favoring the aqueous media interaction.