|
The Shull Group |
||||
55. "Influence of Surface Ordering on the Wetting of Structured Liquids"
Limary, R.; Green, P.F.; Shull, K.R., Eur. Phys. J. E., 8,
103 (2002).
The substrate is shown to induce substantial ordering in diblock copolymer thin
films above the bulk order-disorder transition (ODT) where, thermodynamically,
a phase mixed state is favored. Initially uniform films reorganize to form a
hierarchy of transient surface patterns and stable film thicknesses that depend
on the initial film thickness and on the substrate. Self-consistent field calculations
of the free energy of the system for different situations, depending on the
relative tendency for the different block components to be attracted to the
substrate and/or free surface, provide an explanation of the formation of the
stable film thicknesses. A continuum picture proposed earlier by Brochard et
al. provides an explanation of the wetting characteristics of this system. In
some cases the ordering destabilizes the film so that dewetting occurs (wetting
autophobicity), whereas in other cases the surface ordering results in a kinetic
stabilization of a film that would otherwise dewet.
Download journal-formatted pdf (383 kB, restricted to Northwestern Community)