| Abstract
| - Compositional variation in blends of triblock and diblock copolymer films can be used toadjust the film response to a selective solvent. We investigated the relationship between blend compositionand film structure in ordered films containing poly(styrene-b-2-vinylpyridine) (PS−P2VP) diblocks andPS−P2VP−PS triblocks. The study focuses on films possessing a lamellar morphology. Methanol, astrongly selective solvent for P2VP, is used to swell the films. Since methanol solvates P2VP but not PS,periodic multilayer structures result in which solvent-rich P2VP domains are separated by undissolvedPS domains. The film structure is characterized in the dry and swollen states with neutron reflectivity.Although the dry state morphology dimensions are practically identical for all samples, in the swollenstate films richer in triblock swell less due to higher density of bridges interconnecting the PS domains.Furthermore, in swollen triblock-containing samples, polymer concentration variations in P2VP domainsare suppressed and the PS domains are better aligned with respect to the substrate.
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