Controllable Coalescence Dynamics of Nanodroplets on Textured Surfaces Decorated with Well-Designed Wrinkled Nanostructures: A Molecular Dynamics Study.

The control of coalescence and motion of droplets play a significant role in advanced technology and our daily life, and one of the most important approaches is surface design. Here, the microtextured surfaces decorated with wrinkled substrates are designed and studied for coalescence behaviors. The simulation results show that the coalescence speed would be slower on such surfaces due to the downward movement of the droplets induced by the penetration of atoms into the grooves that delays their movement along the coalescence direction, which is considered as a restriction effect. With the increase of the angles and the interval distance of wrinkled structures, the coalescence time becomes longer and the coalescing process becomes unfavorable, resulting from the enhanced restriction effect. More importantly, a composite substrate possessing the original and sub-wrinkled structures has been designed to tune the coalescence dynamics. The results of this work may not only help shed light on understanding the coalescence behaviors on the wrinkled substrates but also propose a feasible method for controlling the liquid coalescence behavior, which is expected to provide some useful implications for practical applications.