Previous studies have shown that spun-cast films of unentangled synthetic p
olymers commonly dewet inorganic or organic substrates, leading to technolo
gically detrimental results for many applications. We illustrate two strate
gies for influencing polymer film dewetting on inorganic and organic substr
ates. First, the addition of small amounts of C-60 fullerene nanoparticles
to the spin-casting polymer solutions of model synthetic polymers [polystyr
ene (PS) and polybutadiene (PB)] leads to a significant inhibition of film
dewetting on Si. This effect is associated with the formation of a diffuse
fullerene layer near the solid substrate that frustrates the dewetting hole
growth process. Next, we consider polymer branching effects on the dewetti
ng of various generations of hypergraft polymer poly(2-ethyl-2-oxazoline) (
PEOX) films cast on high molecular weight polystyrene substrates. The early
stage of dewetting is found to be similar in a zeroth generation GO hyperg
raft (a comb polymer) and a G2 hyper-graft (resembling a spherical 'micro-g
el' particle). The late stage of dewetting in the G2 films, however, differ
s significantly from the low generation films because of an inhibition of h
ole coalescence in the intermediate stage of film dewetting. This behavior
resembles previous observations of dewetting in 'entangled' polystyrene fil
ms. Thus, the viscoelasticity of the polymer film can have an inhibitory ef
fect on film dewetting, leading to changes in the dewetted film morphology
rather than a suppression of film dewetting. (C) 2001 Elsevier Science B.V.
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