Professor Michael Therien; co-sponsored by the Duke University Energy Initiative's Energy Research Seminar Series
Abstract: We are designing new materials that take advantage of the photochemistry of transition metal complexes. By integrating these metal-coordination moieties into the materials, we can use the specific photochemistry to add in new photo-response into the materials. One kind of responsive material is based on Fe(III) coordination to carboxylate-containing polysaccharides. By tuning the choice of polysaccharide ligand, we can tune the reactivity due to the changing metal-ligand binding interactions. These Fe(III)-polysaccharide hydrogels showed changes in mechanical properties and pore size after light irradiation, and could be used as scaffold materials for tissue engineering. We are now investigating these materials for use in nutrient uptake and release for environmental waste remediation.
We have also created model polymer materials to understand how we could influence and control material properties by tuning the metal ion and ligand. We showed that by changing the geometry of ligand coordination, we could control the mechanical properties of the resulting materials. In addition, such metallopolymers showed reversible photoreactivity, where light irradiation led to softening of the materials.