Dispersions of conjugated polymers from catalytic polymerization in aqueous systems

• Applicant: Professor Dr. Stefan Mecking
• Subject Area: Preparatory and Physical Chemistry of Polymers
• Term: from 2007 to 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 45626153

Conjugated polymers are subject to broad academic and applications-oriented interest. They are technologically important for, e.g., optoelectronics in displays or organic solar cells. While aqueous dispersions of polymer nanoparticles in general have been widely studied, dispersions of conjugated polymers with a hydrocarbon carbon backbone, like polyalkynes, poly(pphenylenes), and poly(phenylene vinylenes) are elusive to date. However, they are an attractive target. Beyond fundamental interest in their preparation and properties, they could resolve issues of processing, which are critical e.g. in the preparation of polymer multilayer structures. Catalytic chain-growth polymerization of acetylene and substituted alkynes in aqueous emulsion to afford polyalkyne dispersions will be investigated with cationic palladium catalysts with bulky phosphine ligands. Catalytic step-growth polymerization of A2 with B2 monomers, and of AB monomers by Suzuki coupling to colloidally stable poly(p-phenylene) dispersions will be investigated. The preparation of dispersions of poly(phenylene vinylenes) by acyclic diene metathesis polymerization with ruthenium alkylidenes is aimed at. Waterinsoluble monomers will be studied for different initial colloidal states of the reaction mixtures (macro-, mini-, and microemulsions), as well as water-soluble and surface active monomers. Suitable lipophilic and water-soluble catalysts will be employed. Polymer micro structures will be characterized. Sizes and structures of the polymer nanoparticles will be elucidated by TEM and AFM. The formation of thin films and their structures will be investigated temperature-dependent, and their physical properties studied preliminarily.

• DFG Programme: Research Grants