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Research Summary:

Our research seeks to develop new methods for the synthesis of functional polymers with the goal of discovering and studying their emergent macromolecular behavior. The approach is rooted in the belief that the convergence of organic, continuous-flow, and polymer chemistries holds the key to making materials smarter, more functional, and more sustainable. The group is currently focused on developing methods to control stereochemistry in ionic polymerizations, uncovering enhanced function in commodity polymers through selective C–H functionalization, and creating automated approaches for the synthesis of unique polymer architectures with novel functions.

Our research program spans each stage from molecular design to material function and will provide students with a diverse and competitive skill set bridging organic and polymer synthesis, small molecule and macromolecule characterization, and applied studies in material science and biotechnology. The goals of the research are inherently interdisciplinary and students will routinely work collaboratively both within and outside of the group to accomplish their scientific and professional goals. We envision our research efforts providing new and potentially useful solutions to challenges in sustainability and human health.

Research Areas of Interest:

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Stereoselective Polymerizations

The tacticity of polymers can significantly affect their thermomechanical properties. In our lab, we have investigated the use of chiral ligands in conjunction with Lewis acids to guide stereoselectivity in the cationic polymerization of vinyl ethers. We have shown that highly isotactic poly(vinyl ether)s have polyolefin-like properties but with polar functionality making them useful materials for a variety of applications. We continue to innovate as we search for new catalytic systems to improve on the state-of-the-art in this field.

Representative Publications:

  • A. J. Teator, T. P. Varner, P. C. Knutson, C. C. Sorensen & F. A. Leibfarth. 100th Anniversary of Macromolecular Science Viewpoint: The Past, Present, and Future of Stereoselective Vinyl Polymerization. ACS Macro Letters, 2020, 9, 1638-1654. (doi)

  • T. P. Varner, A. J. Teator, Y. Reddi, P. E. Jacky, C. J. Cramer & F. A. Leibfarth. Mechanistic Insight into the Stereoselective Polymerization of Vinyl Ethers. J. Am. Chem. Soc. 2020, 142, 17175-17186. (doi)

  • A. J. Teator, F. A. Leibfarth*. Catalyst-Controlled Stereoselective Cationic Polymerization of Vinyl Ethers. Science, 2019, 363, 1439-1443. (doi)

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Polymer C–H Functionalization

C–H functionalization allows for the modification of material properties with the potential to increase material value. In our lab, we apply C–H functionalization to commodity polymers in an effort to discover new properties and upcycle plastic waste.  This application leverages the high-volume and low-cost production of commodity polymers.

Representative Publications:

  • J. B. Williamson, C. G. Na, R. R. Johnson III, W. F. M. Daniel, E. J. Alexanian*, & F. A. Leibfarth*. Chemo- and Regioselective Functionalization of Isotactic Polypropylene: A Mechanistic and Structure–Property Study. J. Am. Chem. Soc. 2019, 141, 12815-12823. (doi)

  • S. E. Lewis, B. E. Wilhelmy Jr. & F. A. Leibfarth*. Upcycling Aromatic Polymers through C–H Functionalization. Chem. Sci., 2019, 10, 6270-6277. (doi)

  • J. B. Williamson; S. E. Lewis; R. R. Johnson III; I. M. Manning; F. A. Leibfarth*. C–H Functionalization of Commodity Polymers. Angew. Chem. Int. Ed. 2019, 58, 8654-8668. (doi)

  • J. B. Williamson; W. L. Czaplyski; E. J. Alexanian* & F. A. Leibfarth*. Regioselective C–H Xanthylation as a Platform for Polyolefin Functionalization. Angew. Chem. Int. Ed. 57, 6261-6265. (doi)

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Flow chemistry in polymer science

Flow Chemistry is a technique that is highly reproducible, allows for rapid mixing and efficient heat transfer, and high sample throughput. In our lab, we use flow chemistry to probe fundamental research as well as explore certain application spaces including 3D printing resins and 19F MRI copolymers. Flow chemistry is well suited to address applications with large structure spaces.

Representative Publications:

  • M. H. Reis, F. A. Leibfarth*, & L. Pitet*. Polymerizations in Flow: Opportunities for Well-Defined Architecturally and Compositionally Complex Polymeric Materials. ACS Macro Letters 2020, 9,c123-133. (doi)

  • M. H. Reis, T. P. Varner, & F. A. Leibfarth*. The Influence of Residence Time Distributions on Continuous-flow Polymerization. Macromolecules 2019, 52, 3551-3557. (doi)

  • M. H. Reis, C. L. G. Davidson IV & F. A. Leibfarth*. Continuous-flow Chemistry for the Determination of Comonomer Reactivity Ratios. Polym. Chem. 2018, 9, 1728-1734. (doi)

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Water Purification

Per- and polyfluorinated alkyl substances (PFAS) contaminate the global water supply, and many are associated with dangerous health effects. A significant challenge in PFAS remediation is that natural organic matter in water is present at one thousand to one million times the concentration of PFAS, leading to nonspecific adsorption of organic matter and leaching of PFAS into effluent water. We aim to address this challenge by designing sorbents which leverage fundamental properties such as fluorophilicity and electrostatic interactions to selectively bind and remove PFAS from water.

Representative Publications:

  • E. Kumarasamy, I. M. Manning, L. B. Collins, O. Coronell*, & F. A. Leibfarth*. Ionic Fluorogels for Remediation of Per- and Polyfluorinated Alkyl Substances from Water. ACS Central Science, 2020, 6, 487-492. (doi)