Chemical Research

Targeting more sustainable organic materials and their applications Visit Archived Chemical Projects

Our chemical research focuses on improving the sustainability of synthetic polymers, either by designing them for degradation or developing route to repurpose them post-use. We are also interested in renewable energy and energy storage. For more details, click on the links below!

Repurposing Plastics for a More Sustainable Future

A relatively new project  in the group is in sustainable materials. Synthetic polymers have an enormous impact on our lives, yet the manner in which they are produced, used, and disposed of is unsustainable. Globally, we produce over 300 million tons of plastics per year, and a stunning >90% of plastics are made from petroleum feedstocks and only a scant 5% of plastics are recycled. Products that are recycled through current mechanical processes are frequently downgraded into lower-quality materials. We are currently exploring methods for “chemical recycling”. This approach includes developing depolymerization procedures and synthetic methods for repurposing degraded polymers into equal-quality or value-added materials.

Redox-active Molecules for Energy Storage

As renewable, but intermittent energy sources become more prevalent, there is an increasing need for scalable, high-capacity methods to store energy. One of our group’s newer projects looks at developing soluble, high-potential organic redox active materials for energy storage applications such as non-aqueous redox flow batteries. We are especially interested in “ambipolar” molecules which can be both oxidized and reduced, enabling devices with the same active species on both sides of the battery. Using a combination of synthetic and electrochemical methods, we are exploring the relationships between molecular structure and properties including potential, cycling stability, and solubility. This work is part of a large, collaborative grant – JCESR – funded by the DOE.

Microplastics Capture & Repurposing

The spread of microplastics throughout the environment is a growing problem with potential for long-term harm to the nation’s ecosystems. Numerous studies have quantified their presence, identified their sources, and pointed out their negative impact on human and environmental health. One major source of microplastics is wastewater, for example effluent from washing machines that contains fibers from clothing. While many larger plastic particles can be sequestered by municipal wastewater treatment facilities, a sizable number of smaller plastics still convey. This project will develop efficient microplastic remediation strategies to capture and eliminate this source of pollution before it enters our waterways. In addition to this goal, the materials used to capture the microplastics will themselves be made of recycled plastics, and the captured microplastics will be upcycled into industrially usable materials. Together, these three project goals will bolster a sustainable plastics economy with less reliance on fossil fuels as well as reduced plastic waste in rivers, lakes, and oceans. This project is part of a funded EFRI through the NSF, and is in collaboration with colleagues Prof. Jose Alfaro, Prof. Brian Love, and Prof. Paul Zimmerman. See also, this press release from UM, for more information.

PFAS Remediation of Contaminated Groundwater

Per- and polyfluoroalkyl substances are both pervasive and persistent. Dubbed ‘forever chemicals’ due to their resistance to biodegradation, a staggering ~98% of the US population has measurable levels of PFAS in their blood. Remediation strategies are urgently needed to attenuate the detrimental impacts of PFASs. One of the most promising remediation technologies involves adsorption of PFASs onto substrates. Our group is pioneering a new class of adsorption materials for PFAS remediation.

Catalyst-Transfer Polycondensation (CTP): Mechanism and Methods

Organic π-conjugated polymers are used as the active components in thin-film solar cells, light-emitting diodes, and transistors. Advantages include tunable optical and electrical properties and the ability to be solution-processed onto large, flexible substrates. For decades the synthetic routes to soluble π-conjugated polymers were dominated by transition-metal-catalyzed step-growth polymerizations. As a result, little control could be exerted over the resulting polymer length, sequence, and distribution. This landscape changed dramatically in 2004, when McCullough and Yokozawa independently identified a living, chain-growth method (now referred to as catalyst-transfer polycondensation (CTP)) for synthesizing poly(3-hexylthiophene). These initial reports ignited a flurry of activity in the field, and more than 150 papers using CTP have been published since 2004. The current challenges include narrow substrate scope, slow precatalyst initiation, and competing side-reactions (e.g., chain-transfer and chain-termination). Our group’s approach to overcome these challenges has involved elucidating their mechanistic underpinnings and utilizing this insight to develop new catalyst systems.