Molecular Insights into the Effect of Temperature
and Functional Groups on the Nonwetting, Prewetting, Partial Wetting,
and Complete Wetting Transitions of Ethanol on Graphite
posted on 2021-08-27, 14:03authored byWaralee Dilokekunakul, Somboon Chaemchuen, Nikom Klomkliang
Adsorption of ethanol on pure and
oxygenated graphite surfaces
in the 120–425 K temperature range was conducted to microscopically
investigate wetting transitions using a Grand Canonical Monte Carlo
Simulation. At temperatures <120 K, ethanol displayed nonwetting
on the pure graphite substrate. Interestingly, in the temperature
range 120–159 K, it transitioned to prewetting and displayed
partial wetting at higher temperatures (159–278 K). Complete
wetting occurred at further temperatures (>278 K). On the isotherm,
partial wetting had two vertical jumps to a complete monolayer (∼6
μmol/m2) and a second layer (∼14 μmol/m2) sequentially. The thin-to-thick film of prewetting had only
one vertical jump to complete two layers simultaneously. When functionalized
graphite was considered, nonwetting and prewetting of pure graphite
at low temperatures (<120 and 120–159 K) could be transferred
to partial wetting. According to the results of this study, the transition
from prewetting to partial wetting occurs not only with higher substrate
affinity but also at higher temperatures.