https://doi.org/10.1140/epjst/e2011-01456-5
Regular Article
Critical assessment of effective interfacial potentials based on a density functional theory for wetting phenomena on curved substrates
1 Center of Smart Interfaces, TU Darmstadt, Petersenstr. 32, 64287 Darmstadt, Germany
2 E. Hála Laboratory of Thermodynamics, Institute of Chemical Process Fundamentals of ASCR, 16502 Prague 6, Czech Republic
3 Department of Physical Chemistry, Institute of Chemical Technology, Prague, 166 28 Praha 6, Czech Republic
4 Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK
a e-mail: andreas.nold09@imperial.ac.uk
b e-mail: a.malijevsky@imperial.ac.uk
c e-mail: s.kalliadasis@imperial.ac.uk
Received:
2
June
2011
Revised:
15
June
2011
Published online:
30
August
2011
In this Letter we examine an effective interfacial Hamiltonian approach for wetting phenomena based on two different density approximations in the framework of a density functional theory. The system under consideration is an attractive spherical wall subject to adsorption by a metastable liquid. We argue that, contrary to a planar geometry, in the spherical case the popular sharp-kink approximation leads to a considerable disagreement for the film thickness with numerical results obtained from density functional theory. We show that the deviation originates from the inaccuracy of the predicted liquid-gas surface tension. We further demonstrate that the prediction can be substantially improved when a soft-interface approximation is adopted, such that the liquid-gas interface is approximated by a smooth monotonic function.
© EDP Sciences, Springer-Verlag, 2011
