Nanoscale fluid structure of liquid-solid-vapour contact lines for a wide range of contact angles
Andreas Nold
David Sibley
Benjamin D. Goddard
Serafim Kalliadasis
2134/17222
https://repository.lboro.ac.uk/articles/journal_contribution/Nanoscale_fluid_structure_of_liquid-solid-vapour_contact_lines_for_a_wide_range_of_contact_angles/9388328
We study the nanoscale behaviour of the density of a simple fluid in the vicinity of an
equilibrium contact line for a wide range of Young contact angles θY ∈ [40◦
, 135◦
]. Cuts of the
density profile at various positions along the contact line are presented, unravelling the apparent
step-wise increase of the film height profile observed in contour plots of the density. The density
profile is employed to compute the normal pressure acting on the substrate along the contact line.
We observe that for the full range of contact angles, the maximal normal pressure cannot solely be
predicted by the curvature of the adsorption film height, but is instead softened – likely by the width
of the liquid-vapour interface. Somewhat surprisingly however, the adsorption film height profile
can be predicted to a very good accuracy by the Derjaguin-Frumkin disjoining pressure obtained
from planar computations, as was first shown in [Nold et al., Phys. Fluids, 26, 072001, 2014] for
contact angles θY < 90◦
, a result which here we show to be valid for the full range of contact
angles. This suggests that while two-dimensional effects cannot be neglected for the computation
of the normal pressure distribution along the substrate, one-dimensional planar computations of
the Derjaguin-Frumkin disjoining pressure are sufficient to accurately predict the adsorption height
profile.
2015-04-10 10:04:42
Adsorption
Contact line
Simple fluid
Disjoining pressure
Derjaguin-Frumkin
Hamiltonian
Mathematical Sciences not elsewhere classified