Smart Polymer Films via RAFT Polymerization from Solid Surfaces
Final Report Abstract
In this project, we first explored and optimized RAFT polymerizations from solid surfaces, by using the approach of immobilizing the controlling RAFT agent at a solid substrate via its stabilizing Z-group. The development of various RAFT agent types for a variety of surfaces, including silica, magnetite, titania, chromium, and gold, expanded the array of surface modification via RAFT polymerization. The results are of importance for technical applications, such as the surfacemodification of polymer filler materials. The propagation kinetics of the surface-confined polymerization was explored in detail and slightly enhanced reactivity of surface-bound macroradicals was found. The main result of the project relates to the interaction of surfaces with polymer chains that carry multiple interactions sites: First, we developed bipedal RAFT agents, which are linked to the surface via two anchor groups, which opened up the formation of polymer loop brushes, i.e., surface-bound polymer films, in which the polymer chains are tethered to the surface via both terminal ends. Secondly, we found out that the interaction of RAFT groups in a grafting-to approach to gold is very powerful for constructing nanocomposites, especially when employing polymers with multi-functionality. Using this approach, we arrived at very well defined nanocomposite materials made of controlled polymer and gold nanoparticles with tunable interparticle distances. Following this strategy, both bulk materials and self-assembled spherical superstructures could successfully be generated. The new strategy opens up a facile pathway to tailored nanocomposites and new sensor materials.
Publications
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‘A Bipedal Silica-Immobilized Azo-Initiator for Surface-Confined Radical Polymerizations’. Australian Journal of Chemistry, 2009, 62, 1473-1478
R. Rotzoll and P. Vana
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‘Surface-Initiated PLP-SEC of Butyl Acrylate and Styrene from Silica Nanoparticles’. Macromolecular Rapid Communications, 2009, 30, 1989-1994
’ R. Rotzoll and P. Vana
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‘RAFT-Polymers with Single and Multiple Trithiocarbonate Groups as Uniform Gold- Nanoparticle Coatings’. Macromolecules 2013, 46, 4862–4871
B. Ebeling and P. Vana
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‘Spherical Gold-Nanoparticle Assemblies with Tunable Interparticle Distances mediated by Multifunctional RAFT Polymers’. ACS Macro Letters, 2013, 2, 1073-1076
C. Rossner, B. Ebeling, and P. Vana
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‘Flipping the Pressure- and Temperature-Dependent Cloud-Point Behavior in the Cononsolvency System of Poly(N-isopropylacrylamide) in Water and Ethanol’. Macromolecules 2014, 47, 1462–1469
B. Ebeling, S. Eggers, M. Hendrich, A. Nitschke, P. Vana
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‘Oberflächen nach Maß’. Nachrichten aus der Chemie (GDCh), 2014, 62, 24-28
B. Ebeling, F. Ehlers, P. Vana
