Topic：Self-Organized Multicompartment Nanostructures from Triblock Terpolymers
Speaker：Professor Axel H. E. Müller
Institute of Organic Chemistry, Johannes Gutenberg Universität Mainz, Germany
Compartmentalization of nanostructures is an important issue since different compartments can have different functions, e.g. loading of different payloads, such as drugs or inorganic nanoparticles. The self-assembly of triblock terpolymers (also known as ABC triblock copolymers) in solution and in the bulk is ideally suited for such a task. A typical example is polystyrene-block-polybutadiene- block-poly(methyl methacrylate) (PS-b-PB-b-PMMA; SBM). Compartmentalization can occur either in the corona or in the core. We have prepared corona-compartmentalized nanoparticles (Janus spheres, cylinders, or disks) by crosslinking domains in the bulk nanostructures of triblock terpolymers. These Janus micelles have superior properties as interfacial agents, as stabilizers in emulsion polymerization, as compatibilizers of polymer blends, or for the solubilization of carbon nanotubes. We present a guided, hierarchical self-assembly of triblock terpolymers into multicompartment-core micelles (MCMs) of different shapes and sizes, simply by choosing the right solvent conditions and solvent sequences. These MCMs can reversibly form spherical shapes like footballs or worm-like structures with alternating compartments of PS and PB, with a corona of PMMA. The different compartments can be loaded with various nanoparticles or drugs. Co-assembly leads to new, complex linear structures at a further level of hierarchy and allows control of the chain length up to 30 μm. We also demonstrate a novel, solution-based approach to Janus micelles by crosslinking the patches on a spherical MCM. In contrast to our former bulk morphology approach this new approach for the first time provides soft Janus micelles with adjustable Janus balance, i.e. adjustable fraction of polymer chains forming one face. This balance is important, e.g., for their use as dispersants of carbon nanotubes.
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 C. V. Synatschke, et al. ACS Nano 2014. DOI: