Speaker: Dr. Bryan Tuten, Queensland University of Technology
Title: “Around the World in 80 (thousand) Reactions: Functional and Dynamic Soft Matter Materials from the Nano- to Macroscale”

Abstract:  This research presentation will highlight some of my group’s recent efforts in exploring “non-traditional” ingredients and methodologies for functional macromolecular materials. Project 1: We introduce a single-chain nanoparticle (SCNP) system capable of catalyzing the photooxidation of nonpolar alkenes up to three times more efficiently than an equivalent small-molecule photosensitizer at an identical concentration under green light. Specifically, we construct a polymer chain constituted of poly(ethylene glycol) methyl ether methacrylate and glycidyl methacrylate which we compact via multifunctional thiol-epoxide ligation and functionalize with Rose Bengal (RB) in a one pot reaction, affording SCNPs with a hydrophilic shell and hydrophobic photocatalytic regions. Our approach demonstrates that SCNP-based catalysts can afford enhanced photocatalysis via confinement effects in a homogeneous reaction environment. Project 2: We introduce a four component Passerini polymerization utilizing sterically bulky isocyanide monomers. Under typical Passerini conditions, bulky isocyanides do not react within standard Passerini reaction timescales (hours). We overcome this challenge via the unique physiochemical conditions present in a vortex fluidic device, reducing the reaction time to 2 h on average. Under these high-shear thin-film conditions, bulky isocyanides are readily incorporated into the multicomponent polymerization without the need of high-pressure or temperature. Finally, we demonstrate that the four-component approach using functional cyclic anhydrides allows for post-polymerization modification. Project 3: We introduce chalcogen squares via selenadiazole motifs as a new class of dynamic supramolecular bonding interactions for the modification and control of soft matter materials. We showcase selenadiazole motifs in supramolecular networks of varying primary chain length prepared through polymerization using tandem step-growth/Passerini multicomponent reactions (MCRs). Compared to controls lacking the selenadiazole motif, these networks display increased glass transition temperatures and moduli due to the chalcogen bonding linkages formed between chains. These elastomeric networks were shown to autonomously heal at room temperature, retaining up to 83% of the ultimate tensile strength. Lastly, we use post-polymerization modification via the Biginelli MCR to add selenadiazole motifs to narrowly dispersed polymers for controlled topology in solution. Chalcogen squares via selenadiazoles introduce an exciting exchange mechanism to the realm of dynamic materials.

The Chemistry and Biochemistry Departmental Seminar Series covers a broad range of fields in the Chemical and Biochemical Sciences. In past seminars, scientists from Academia, Government, and Industry have presented their most recent discoveries and contributions in their respective areas. This Seminar Series offers students and faculty the opportunity to interact directly with other leaders in their specializations and to gain a good overview of the entire range of fields in Chemistry and Biochemistry.

This seminar will take place in person and virtual.