Stimuli-responsive polymers adapt to their surrounding and posses a wide range of applications in the fields of diagnostics, drug delivery, tissue engineering, biosensors, and optical systems.1 The characteristic property that makes stimuli-responsive polymers receptive to their environment is the dynamic bonds between the subunits in the polymer chains. Typically, such dynamic bonding invovles hydrogen bonding, stacking, or metal-ligand coordination.2 Among several such assembly, linear/branched polymers made of metal-ligand coordination hold particular interest due to their tunable and highly directional non-covalent bonds. These metallosupramolecular polymers are formed by self –assembly of designed subunits by metal-ligand interaction.3 The resultant polymer's property can be tuned by changing monomer structure, nature of the binding groups, substituents on the binding group, and the metal ions of interest.4 These materials can also be used for potential applications as gels and thin film fabricates.
The present seminar will outline the design, synthesis, properties, and important applications of metallosupramolecular polymers. A novel synthetic route for supramolecular polymer gel by ring-opening polymerization of cyclic monomers followed by functionalization of a metal-binding group to the main chain will be presented. We have synthesized poly(norbornene anhydride-co-cyclohexene oxide) followed by the functionalization of the polymer by thiol-ene click chemistry. The resultant functionalized polymer showed immediate gelation with lanthanides (Eu3+ and Tb3+) acetate to form luminescent metallosupramolecular polymer gel. We hypothesize that such gels could exhibit stimuli-responsive properties in presence of stimuli such as pH and mechanical force. Rationale for such expected behavior will also be discussed in the seminar.
References
1. Stuart,M.; Huck,W.; Genzer,J.; Muller,M.; Ober,C.; Stamm,M; Sukhorukov,G.; Szleifer,I.; Tsukruk,V.; Urban,M.; Winnik,F.; Zauscher,S.; Luzinov,I.; and Minko,S., Nature Materials, 2010, 9, 101–113.
2. Espinosa,M.; Fiore,G.; Weder,C.; Foster,E.; and Simon,Y., Progress in Polymer Science, 2015, 49, 60–78.
3. Constable,E., Chem. Commun.,1997, 12, 1073-1080.
4. Herbert,K.; Schrettl,S.; Rowan,S.; and Weder,C., Macromolecules, 2017, 50, 8845−8870.