Self-assembly of functional polymers

Bridging the gap between the molecular and the macroscopic world is one of the great challenges in science and technology today. Polymers, being intermediate in size between molecules and macroscopic objects, are preeminently suitable to perform this task. In this PIONIER-proposal, concepts of self-assembly by hydrogen bonding advanced by us will be developed further and will be combined with the order in block copolymers induced by microphase separation to realize functional materials with organization on a length scale of 10-100 nm. In a complementary part of the proposal, a direct link between macroscopic shape and molecular functionality will be made, mediated by the mechanical properties of elastomers, which contain metal coordination complexes. The proposal consists of three related, but distinct projects, which focus on the use of polymeric materials for creating order on the nanometer scale (1 and 2) and for direct transduction of macroscopic into molecular stimuli (project 3). 1) Supramolecular Block Copolymers Introduction of highly directional hydrogen bonding interactions in the self-assembly of block copolymers, is the focus of this project. The use of hydrogen bonds is a concept strongly promoted by us in the context of “supramolecular polymers”. In the present proposal this concept will be applied to block copolymers with the objective to obtain highly ordered architectures on a nanometer scale with less effort, with smaller block sizes, with higher processability, and with the possibility to obtain responsive materials, all due to the reversible nature of the supramolecular interactions employed. 2) Surface Functionalization and Patterning Surfaces and interfaces are where the interconnection between the nanoscopic and the macroscopic worlds is made. In this project, the toolbox of functionalized polymers and their morphologies, used and developed in project 1, are applied to surfaces. The reversibility of the hydrogen bond will be employed to obtain responsive polymer films with tunable surface properties. Patterning of surfaces with supramolecular polymers offers many potential advantages over the use of conventional block copolymers, including easier ways of aligning and orienting lamellar and cylindrical morphologies, and the possibility to include responsive blocks in the architecture. 3) Mechanoresponsive Polymers The use of elastomers to change the shape of covalently incorporated chromophores and catalysts in a controlled way is a scarcely explored area of research. This concept – directly connecting macroscopic with molecular scale phenomena – offers the possibility to tune the optical properties of polymers, or to use this response as a tool to investigate elastic deformation at a molecular scale. Probably the most exciting prospect of this topic is the possibility to improve the performance of transition metal catalysts by incorporating them into polymers which are subject to static or dynamic deformation. Funding for PhD students and Postdoctoral students is requested to perform the research outlined above. Furthermore, a modest contribution for equipment and experimental techniques new to the laboratory is asked for. The projects described in this proposal are based on a background in “macromolecular engineering”, and have a focus on fundamental insights. However, the scope of the proposal goes beyond these limits, both in terms of expertise and of potential technological impact. For this reason, and in order to realize the full potential of the topics, much work will be performed in local, national and international cooperation with researchers in specific disciplines. The projects are embedded in the infrastructure of the department of chemical engineering at the TU/e, and form an extension of the interest of the TU/e in both polymeric materials and nanotechnology. The Eindhoven University of Technology (TU/e) strongly supports the application and has agreed to provide matching funds up to 50% of the budget for the proposal.