title: Structural instabilities in lamellar diblock copolymer thin films during solvent vapor uptake.
abstract: We have studied the structural rearrangements in a lamellae-forming poly(styrene-b-butadiene) film during exposure to toluene vapor. Real-time, in situ grazing-incidence small-angle X-ray scattering allowed us to identify distinct kinetic regimes: First, the lamellae swell linearly, and the blocks stretch uniaxially. Then, the blocks relax to a more globular molecular conformation, and the lamellar thickness abruptly shrinks again. The increased interfacial area culminates in a dramatic instability causing a major rearrangement of the lamellar stack and the formation of new lamellae. Finally, the lamellar thickness levels off, and the interfaces flatten again.
authors.affiliation: Technische Universität München, Physikdepartment E13, James-Franck-Strasse 1, 85747 Garching, Germany. christine.papadakis@ph.tum.de
authors.forename: Christine M
authors.initials: CM
authors.lastname: Papadakis
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Di
authors.forename: Dorthe
authors.initials: D
authors.lastname: Posselt
authors.forename: Detlef M
authors.initials: DM
authors.lastname: Smilgies
mesh_terms: D011108:Polymers / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry*; D013057:Spectrum Analysis; D014835:Volatilization
chemical_list: D011108:Polymers; D012997:Solvents