Metal-coordination interactions are promising chemical motifs for the design of bioinspired polymeric materials that mimic the mechanical performance of biogenic materials such as the arthropod fangs and mussel byssal threads. Building upon the use of such motifs for the design of associative polymer gels, we demonstrate a bioinspired strategy to introduce additional mechanical reinforcement and novel functionalities into metal-coordinate hydrogels, by using the strongly metal-coordinating ligands as templates for the mineralization of metallic nanoparticles in the hydrogels in situ. Using polymeric hydrogels functionalized with iron-coordinating phenolic compounds – nitrocatechol, catechol, and pyrogallol – as mineralization templates, we show that the in situ growth of iron oxide nanoparticles in the hydrogels results in a significant increase in the stiffness of the hydrogel network compared to metal-ion-coordinated hydrogels, as well as an emergence of magnetism in the hydrogel. We thus demonstrate a general strategy to use metal-coordinate networks as scaffolds for the bottom-up synthesis of mechanically-robust and stimuli-responsive nanocomposite polymer networks, which may inform the design of soft materials for complex mechanical function such as soft robotics, energy harvesting, and cellular interactions.

In situ mineralization in metal-coordinate polymeric materials

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.