Hierarchical self-assembly of miktoarm star polymers containing a?polycationic segment: A general concept

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• 作者：Andreas Hanisch ; Andr¨¦ H. Gr?schel ; Melanie F?rtsch ; Tina I. L?bling ; Felix H. Schacher ; Axel H.E. M¨¹ller
• 关键词：Miktoarm star polymer ; Polyelectrolyte ; Hierarchical self-assembly
• 刊名：Polymer
• 出版年：2013
• 出版时间：2 August, 2013
• 年：2013
• 卷：54
• 期：17
• 页码：4528-4537
• 全文大小：2681 K

文摘

We recently introduced a concept for the counterion-mediated hierarchical self-assembly of an amphiphilic ABC miktoarm star terpolymer in aqueous media into micrometer-sized compartmentalized particles with a highly periodic lamellar fine structure (¡°woodlice¡±). Herein, we extend this concept to different miktoarm star polymer systems containing a polycationic segment. The presence of a poly(N-methyl-2-vinylpyridinium) (P2VPq) block and its interaction with iodide/triiodide counterions is crucial. In analogy to linear diblock copolymer systems the hydrophilic/hydrophobic balance of polybutadiene-arm-poly(N-methyl-2-vinylpyridinium iodide)-arm-polystyrene miktoarm star terpolymers determines the morphology of the primary building blocks (spherical micelles and cylindrical micelles/vesicles) and the obtained superstructures (stacked lamellar structures and multilamellar vesicles) during this hierarchical process. When an ABA' miktoarm star copolymer (polystyrene-arm-poly(N-methyl-2-vinylpyridinium iodide)-arm-polystyrene) without a dynamic core-forming block was investigated, a?different mechanism into ¡°woodlouse¡± structured aggregates via aggregation and deformation of intermediate vesicles was found. The individual steps of the different self-assembly processes were investigated by transmission electron microscopy and additionally supported by dynamic light scattering, differential scanning calorimetry, and small-angle X-ray scattering.