Collapse of polymer brushes grafted onto planar ... - Wageningen UR

WETTING OF AN ANNEALED POLYELECTROLYTE BRUSH, A NUMERICAL SCF STUDY
F.A.M. Leermakers 1) , A. Mercurieva 2) , E.B. Zhulina 2) , T.M. Birshtein 2)
1) Laboratory of Physical Chemistry and Colloid Science, Wageningen University,
Dreijenplein 6, 6703 HB Wageningen, The Netherlands
2)
Institute of Macromolecular Compounds of the Russian Academy of Sciences,
199004, St. Petersburg, Russia
email: frans@fenk.wau.nl
ABSTRACT
In this poster we will discuss the wetting properties of an annealed polyelectrolyte brush in an oil-salted water
system. The ionic strength is chosen as the control parameter. The salted water interacts with the solid
substrate as well as with the annealed brush. The first type of interaction has a short-range character; the
other one is long range (at least proportional to the brush height). One can envision wetting transitions due to
both interactions. The two wetting transitions appear to be of the first-order type and interfere with each other.
The pre-wetting lines associated to these transitions cross and a triple point is found. At this triple point three
(microscopic) film thicknesses coexist. There can only be one wetting transition and therefore one part of one
of the pre-wetting lines is meta-stable in between a hidden wetting transition and the triple point. The other
pre-wetting line is attached to the true wetting transition and has a kink at the triple point.