Structural instabilities in lamellar diblock copolymer thin films during solvent vapor uptake.
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.
Papadakis
Christine M
CM
Technische Universität München, Physikdepartment E13, James-Franck-Strasse 1, 85747 Garching, Germany. christine.papadakis@ph.tum.de
Di
Zhenyu
Z
Posselt
Dorthe
D
Smilgies
Detlef M
DM
D011108:Polymers / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry*; D013057:Spectrum Analysis; D014835:Volatilization
D011108:Polymers; D012997:Solvents