Eur. Phys. J. E 1, 249-262
Stability of droplets and channels on homogeneous and structured surfaces
P. Lenz - R. Lipowsky
Max-Planck-Institut für Kolloid- und Grenzflächenforschung, 14424 Potsdam,
Germany
lenz@cmtql.harvard.edu,
lipowsky@mpikg-golm.mpg.de
Received 4 August 1999
Abstract
Wetting of structured or imprinted surfaces which leads to a variety
of different morphologies such as droplets, channels or thin films is
studied theoretically using the general framework of surface or
interface thermodynamics. The first variation of the interfacial free
energy leads to the well-known Laplace equation and a generalized
Young equation which involves spatially dependent interfacial
tensions. Furthermore, we perform the second variation of the free
energy for arbitrary surface patterns and arbitrary shape of the
wetting morphology in order to derive a new and general stability
criterion. The latter criterion is then applied to cylindrical
segments or channels on homogeneous and structured surfaces.
PACS
68.45.Gd Wetting -
68.10.Cr Surface energy (surface tension, interface tension,
angle of contact, etc.) - 47.20.Dr Surface-tension-driven instability
Copyright EDP Sciences, Società Italiana di Fisica, Springer-Verlag
