Regensburg 2010 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 14: Poster: Interfaces and Thin Films

CPP 14.25: Poster

Montag, 22. März 2010, 16:30–18:00, Poster C

Effect of chain architecture on microdomain orientation in thin films of block copolymer supramolecular assemblies — •Bhanu Nandan and Manfred Stamm — Leibniz-Institut für Polymerforschung Dresden, Hohe Strasse 6, 01069 Dresden

The phase behaviour of supramolecular assemblies (SMA) formed by poly(4-vinylpyridine)-b-polystyrene-b-poly(4-vinylpyridine) (P4VP-b-PS-b-P4VP) triblock copolymer with 2-(4'-hydroxybenzeneazo)benzoic acid (HABA) was investigated with respect to the molar ratio (X) between HABA and 4VP monomer unit. The results were compared with SMAs formed by a PS-b-P4VP diblock copolymer of similar composition as the triblock but half the molecular weight to ascertain the effect of chain architecture on microphase separation. In bulk, both the di- and triblock SMAs showed composition dependent morphological transitions which could be tuned by HABA/4VP molar ratio. In thin films also, both the di- and triblock SMAs showed more or less similar morphological transitions depending on X. Interestingly, the domain orientation of the cylindrical or lamellar microdomains in the SMAs was influenced by the chain architecture of the block copolymer. After chloroform annealing whereas the diblock SMAs showed in-plane orientation of the domains, triblock SMAs showed perpendicular domain orientation. The perpendicular orientation of the microdomains in triblock was favored since it allowed the mid PS blocks to acquire normal distribution of loop and bridged conformations. *This research was supported by the priority program of DFG (SPP1165, Project No. STA324/31).