Supramolecular Polymers and Crosslinkers to Control Structure, Properties, and Performance in Polymer Networks and Nanomaterials

Zoom Link

Synthetic polymers have played a significant role in society over the past century. The continued development of advanced polymerization techniques and new chemical designs has accelerated the pace at which materials have been produced. Traditionally, many commercial materials such as polyurethane foams, silicones, epoxy sealants, and rubber car tires have consisted of crosslinked polymer networks. Generally speaking, the crosslinkers used to hold these materials together are not dynamic after the network has been formed. Over the past few decades, chemists have sought to develop next-generation functional materials with emergent properties by envisioning the crosslinkers to be much more than just a static, covalent tether. Instead, so-called ‘intelligent’ or ‘smart’ materials have been achieved through molecular programming of the precursor components, such that they are able to ‘sense’ and respond to external environmental cues, like heat and light for example, or possess unique pathways of absorbing and dissipating external forces via dynamic, well-defined topologies.
My research group at Washington University in St. Louis (WashU) is focused on designing the next generation of dynamic and reconfigurable materials that simultaneously take advantage of covalent and non-covalent chemical bonding. Specifically, we design functional polymers and crosslinkers with supramolecular properties and/or precise topologies that adopt unique pathways of self-assembly and activation. Thus, we create functional materials through a bottom-up approach, i.e., nano to macroscale, to emulate Nature’s forms of molecular recognition or function, while simultaneously possessing the enhanced robustness and durability that is expected of next-generation synthetic materials. In my talk, I will discuss (1) the synthesis of novel redox- and photo-responsive polymers and soft materials for applications in hydrogel actuators, visible-light photoredox patterning, and self-healing, underwater adhesives, (2) our journey into the impact the mechanical bond has on materials comprised of mechanically interlocked polymers and crosslinkers, and lastly, if there is time, (3) our efforts to rationally design and self-assemble highly functional block copolymers into nanoparticles for applications in combination antimicrobial delivery.