title: Interface-enforced complexation between copolymer blocks.
abstract: Binary diblock copolymers and corresponding ternary miktoarm stars are studied at oil-water interfaces. All polymers contain oil-soluble poly(propylene oxide) PPO, water-soluble poly(dimethylaminoethyl methacrylate) PDMAEMA and/or poly(ethylene oxide) PEO. The features of their Langmuir compression isotherms are well related to the ones of the corresponding homopolymers. Within the Langmuir-trough, PEO-b-PPO acts as the most effective amphiphile compared to the other PPO-containing copolymers. In contrast, the compression isotherms show a complexation of PPO and PDMAEMA for PPO-b-PDMAEMA and the star, reducing their overall amphiphilicity. Such complex formation between the blocks of PPO-b-PDMAEMA is prevented in bulk water but facilitated at the interface. The weakly-interacting blocks of PPO-b-PDMAEMA form a complex due to their enhanced proximity in such confined environments. Scanning force microscopy and Monte Carlo simulations with varying confinement support our results, which are regarded as compliant with the mathematical random walk theorem by Pólya. Finally, the results are expected to be of relevance for e.g. emulsion formulation and macromolecular engineering.
authors: Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52056 Aachen, Germany. plamper@pc.rwth-aachen.de.
authors: Alexander A
authors: AA
authors: Steinschulte
authors: Weinan
authors: W
authors: Xu
authors: Fabian
authors: F
authors: Draber
authors: Pascal
authors: P
authors: Hebbeker
authors: Andre
authors: A
authors: Jung
authors: Dimitri
authors: D
authors: Bogdanovski
authors: Stefanie
authors: S
authors: Schneider
authors: Vladimir V
authors: VV
authors: Tsukruk
authors: Felix A
authors: FA
authors: Plamper