Metallopolymers as self-healing materials

Metallopolymers represent an interesting class of supramolecular polymers. Their properties can be tuned by the selection of the attached/incorporated ligand as well as the choice of the corresponding metal ion.[1] In this manner, also reversible interactions, i.e. on the one side undirected ionic interactions between positively charged metal complexes and negatively charged counterions as well as on the other side directed ligand-metal interactions can be introduced. These interactions are the basis for the introduction of self-healing properties, comparable to the natural archetype (reversible metal complexes can be found within mussel byssus threads).[2] Different methacrylate-based polymers containing ligands (i.e. terpyridine) in the sidechain have been synthesized. These materials have been used for the fabrication of cross-linked metallopolymer networks. The influence of the comonomers, the binding ligand as well as the metal ion on the resulting cross-linked polymer films has been investigated in detail. Additionally the influence of the counter ion on the polymeric films has been studied. The self-healing behavior of these materials was investigated. Lastly, the basic mechanisms behind the self-healing processes within these metallopolymers will be discussed in detail