@Article{CiCP-23-1191,
author = {},
title = {Self-Propelled Jump Regime in Nanoscale Droplet Collisions: A Molecular Dynamics Study},
journal = {Communications in Computational Physics},
year = {2018},
volume = {23},
number = {4},
pages = {1191--1201},
abstract = {<p style="text-align: justify;">Self-propelled jump of droplets is among the most striking phenomena in
droplet collisions on substrates. Self-propelled jump phenomena of droplets have been
observed in experiments, which have also been reproduced in macro- or mesoscale
numerical simulations. However, there have been few previous studies on the phenomena
at nanoscales. To unravel the dynamics and mechanisms of nanoscale binary
droplet collisions on substrates, head-on collision processes of two identical water
droplets with diameters of 10nm on graphite substrates are investigated by molecular
dynamics (MD) simulations. By varying the impact Reynolds number of binary
droplet collisions on hydrophilic or hydrophobic substrates, we successfully reproduce
self-propelled jump of droplets on a super-hydrophobic surface with a contact
angle of 143<sup>◦</sup> and a relatively high impact Reynolds number of 17.5. Parametric studies
indicate that both high impact Reynolds numbers and high hydrophobicity promote
self-propelled jump. Moreover, the criterion based on the Ohnesorge number derived
from the mesoscopic self-propelled jump regime is insufficient to precisely predict a
nanoscale self-propelled jump phenomenon. For this reason, our study includes the
impact Reynolds number and the substrate properties like contact angle as additional
criteria to refine and extend the current theory for the self-propelled jump behaviours
to nanoscales. The study provides insight into the mechanism of self-propelled jump
phenomenon at nanoscales.</p>},
issn = {1991-7120},
doi = {https://doi.org/10.4208/cicp.OA-2016-0253},
url = {http://global-sci.org/intro/article_detail/cicp/11211.html}
}