Furthermore, the preparation of cross-linked materials in higher concentrations has been performed. Gels have been obtained and studied regarding their swelling behavior.Poly(methyl methacrylate) copolymers bearing terpyridine moieties in the polymer side chain were synthesized using a free radical polymerization process. The obtained copolymers were characterized by 1H NMR spectroscopy and gel permeations chromatography (GPC), respectively. Supramolecular cross-linking of the terpyridine-containing copolymers was investigated upon addition of transition metal ions (Fe(II) and Zn(II)) in diluted solutions. The complexation reactions were followed in detail by UVvis and viscosity titration experiments. Addition of iron(II) ions led to a higher viscosity compared to zinc(II) ions, due to the higher stability of the iron(II)- bis-terpyridine complexes. The complex formation could be reversed completely by addition of HEEDTA which is a strong competing ligand. It clearly demonstrates the reversible properties of the investigated materials.
|Published - 2008