Toward Anisotropic Hybrid Materials: Directional Crystallization of Amphiphilic Polyoxazoline-Based Triblock Terpolymers

• Published in: ACS nano Vol. 9; no. 10; pp. 10085 - 10098
• Main Authors: Rudolph, Tobias, Lühe, Moritz von der, Hartlieb, Matthias, Norsic, Sebastien, Schubert, Ulrich S, Boisson, Christophe, D’Agosto, Franck, Schacher, Felix H
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 27.10.2015
• Subjects: Chemical Sciences; crystallization; self-assembly; fiber-like micelles; poly(2-oxazoline)s; triblock terpolymer; polyethylene
• DOI: 10.1021/acsnano.5b03660
• ISSN: 1936-0851

We present the design and synthesis of a linear ABC triblock terpolymer for the bottom-up synthesis of anisotropic organic/inorganic hybrid materials: polyethylene-block-poly(2-(4-(tert-butoxycarbonyl)amino)butyl-2-oxazoline)-block-poly(2-iso-propyl-2-oxazoline) (PE-b-PBocAmOx-b-PiPrOx). The synthesis was realized via the covalent linkage of azide-functionalized polyethylene and alkyne functionalized poly(2-alkyl-2-oxazoline) (POx)-based diblock copolymers exploiting copper-catalyzed azide–alkyne cycloaddition (CuAAC) chemistry. After purification of the resulting triblock terpolymer, the middle block was deprotected, resulting in a primary amine in the side chain. In the next step, solution self-assembly into core–shell-corona micelles in aqueous solution was investigated by dynamic light scattering (DLS) and transmission electron microscopy (TEM). Subsequent directional crystallization of the corona-forming block, poly(2-iso-propyl-2-oxazoline), led to the formation of anisotropic superstructures as demonstrated by electron microscopy (SEM and TEM). We present hypotheses concerning the aggregation mechanism as well as first promising results regarding the selective loading of individual domains within such anisotropic nanostructures with metal nanoparticles (Au, Fe3O4).