Polymers

Electricity, Air, and Plastic Recycling

Daniel Morton — Tue, 17 Jun 2025 21:15:48 +0000

Electricity, Air, and Plastic Recycling Daniel Morton Tue, 06/17/2025 - 15:15

Daniel Morton

This collaboration between four RASEI Fellows shows how electricity can be used to impart ‘superoxide powers’ to oxygen gas molecules from air, enabling the efficient recycling of PET plastics.

In 2012, 32.5 million tons of plastic waste was produced globally. 4.5 million tons of which was poly(ethylene terephthalate), better known as PET. You likely know this as the plastic that has the number 1 in the middle of the recycling symbol. PET is used extensively in materials such as packaging, textiles, films, and flexible electronics. By far and away its main use is in bottled drinks. PET is considered a standout material, it is strong, chemically resistant, transparent, and impermeable to water. Even better, it is possible to recycle PET – it has its own number, right? Unfortunately, this is not quite the full story. Globally, it is estimated that only about 9% of plastic waste is recycled, and while PET waste is one of the best performers, with a recycling rate approaching between 25-30%, the majority of plastic, even PET, ultimately ends up in landfills, incinerated, or worse, polluting our environment. The magnitude of this problem is only increasing; in 2024 the world generated an estimated 240 million tons of plastic waste, representing more than eight-fold increase in 12 years and highlighting the need for more effective solutions.

This teams bring together four RASEI Fellows, Oana Luca (Chemistry, ɫ��Ƶ��), Seth Marder (Chemistry and Chemical & Biological Engineering, ɫ��Ƶ��), Stephen Barlow (RASEI, ɫ��Ƶ��) and Elisa Miller (Chemistry and Nanoscience, NREL) to address the accelerating issue of plastic waste. While there are many parts to this global challenge, this research focuses on how we recycle plastics, specifically PET. When we think about recycling plastic, most of us just think about throwing a plastic bottle, or piece of packaging, into a recycling bin. We rarely give it much thought after that. This really is just the start of a journey that is more complex than many realize. There are actually several different approaches to giving plastic a second life. The most common, and perhaps the method that most people are familiar with, is mechanical recycling.

Think of mechanical recycling like an industrial washing machine combined with a paper shredder. Plastic items are collected, sorted, cleaned, and then chopped up into small flakes or melted down into pellets that can be molded into new products. This approach is efficient and works great for clean, single-type plastics, but there are some significant limitations with this process. In the same way that a white shirt can’t be perfectly restored after being mixed with brightly colored laundry, plastic quality degrades each time it goes through mechanical recycling. This reduction in quality is stark, most mechanically recycled plastics can only go through the process 2-3 times before they become unusable. This makes it financially unattractive and severely limits the long-term efficacy of recycling. How can this be an enduring solution if we can only recycle something a couple of times?

Chemical recycling takes a very different route, instead of the ‘brute-force’ approach of just melting and reshaping the plastic, it employs a more surgical method, breaking down the plastic polymer chains into their constituent molecular building blocks. These molecular building blocks can then be used, either to make new plastics, or for other applications. Because the new plastics are made with molecular control, there is no degradation in quality, and the materials can be recycled over and over, essentially as many times as you wish. Instead of a washing machine combined with a paper shredder, this is more like a LEGO set, where the model can be taken apart brick by brick and be used to build something entirely new. This research describes a new approach to depolymerization, a class of chemical recycling.

The research described in this RASEI collaboration, just published in ACS Sustainable Chemistry and Engineering, offers a new, more efficient approach. By passing an electric charge through the reaction, electrons can be used to activate molecules that can then go on to react with the polymer. In a recent study, that used additive molecules as electron shuttles, the team observed the addition of electrons to oxygen gas molecules in small amounts present in the reaction, that were originally thought to be innocent bystanders in the mixture. This led the team to hypothesize that oxygen gas molecules, directly from air, could be chemically reduced, (that is that they take on an extra electron), leading to the formation of a relatively stable superoxide radical anion, O₂^·–. This activated superoxide now acts in place of the solvent and reacts directly with the polymer. Since the superoxide has an extra electron gained from the electric current, the negatively charged superoxide molecule reacts with the centers that have a positive charge on the polymer. This results in the breaking down of the polymer in a predictable and selective fashion, and the incorporation of oxygen into the building blocks instead of the solvent molecules, leading to the reliable and reproducible formation of the same molecules that were used to build the polymer in the first place. The LEGO bricks are formed cleanly and are ready to be used again, with no degradation in molecular quality. This work demonstrates this technology on a range of different plastics using air, arguably one of the most abundant and cheap reagents, as the primary oxygen source, and all done at room temperature and pressure, a huge improvement on other chemical recycling approaches. While the results are promising and show good efficiencies, this lab-based proof of principle still has a number of challenges to solve before it can be scaled up to meaningful levels.

Today, most plastics are recycled using mechanical recycling, which is like the combination of an industrial washing machine and a paper shredder, producing low-quality products and reducing the possibility of future recycling, leading many to explore chemical recycling as an alternative to gain access to more valuable chemical building blocks. Current mainstream chemical recycling methods are like using a sledgehammer, they typically require high temperatures and lots of energy to break the chemical bonds. The development of electrochemical methods offers a more controlled approach, breaking down plastics at the molecular level and reliably producing build blocks that can be used over and over again. New recycling technologies could transform how we handle plastic waste, opening the door to recycling previously un-recyclable plastics, doing it in a more energy efficient way, producing higher quality recycled plastics, and making recycling economically competitive with virgin plastic production from oil. The development of more effective and general recycling strategies isn’t just an environmental imperative. As plastic waste continues to accumulate, it is rapidly becoming an economic necessity. We already have so much plastic in the world, if we can develop methods to regenerate and reuse the building blocks from plastic waste it will turn landfills into gold mines.

How amazing would it be if instead of society wasting plastics, filling landfills, and polluting our environments, we viewed used plastics as a commodity for future applications?

June 2025

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RASEI Fellow Kat Knauer selected as member of the 2025 C&EN’s Talented 12

Daniel Morton — Fri, 23 May 2025 18:27:40 +0000

RASEI Fellow Kat Knauer selected as member of the 2025 C&EN’s Talented 12 Daniel Morton Fri, 05/23/2025 - 12:27

Daniel Morton

Kat has been highlighted for her work developing sustainable and recyclable plastics.

2025 Talented 12 Press Release

2025 Talented 12 Overview

Kat Knauer Profile

For the last decade Chemical and Engineering News (C&EN), the weekly industrial press for the chemistry and chemical engineering fields published by the American Chemical Society (ACS), has selected a dozen early-career scientists to highlight. Each year the Talented 12 introduces researchers from across disciplines who are using their chemistry know-how to make societal impacts.

This year more than 350 young chemists and chemical engineers were nominated, which was whittled down to 12 by the panel reviewing the different impacts of the research. Research done by members of the class include materials that could help hearts heal, measuring aerosol particles to understand climate change, controlling charged particles to improve energy efficiency, using biology to solve environmental problems, explaining chemical movement with math, understanding pollutants, preventing drug side effects, providing insights into disease, improving food security, transforming waste water into valuable minerals and harnessing electrons to clean chemicals.

RASEI Fellow Kat Knauer was highlighted for her research on developing sustainable and recyclable plastics, driven by her passion for solving the plastic waste crisis. Check out the full story about the Talented 12 and the profile on Kat Knauer for all the details.

May 2025

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Air-Enabled Electricity-Driven Depolymerization of Polyesters

Daniel Morton — Sun, 13 Apr 2025 19:26:24 +0000

Air-Enabled Electricity-Driven Depolymerization of Polyesters Daniel Morton Sun, 04/13/2025 - 13:26

ACS SUSTAINABLE CHEMISTRY & ENGINEERING, 2025, 13, 16, 5818-5827

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SPECS 2025 Annual Meeting

Daniel Morton — Wed, 12 Feb 2025 23:49:33 +0000

SPECS 2025 Annual Meeting Daniel Morton Wed, 02/12/2025 - 16:49

Daniel Morton

SPECS EFRC

In February of 2025 RASEI hosted the 2025 SPECS Annual Meeting, bringing together researchers from across the nation to discuss recent updates and plan future research.

The Center for Soft PhotoElectroChemical Systems, or SPECS, is a US Department of Energy funded Energy Frontiers Research Center. The focus of SPECS is to understand and develop organic polymers, so called soft materials, that can be used in transporting electrons, for applications in batteries, electronics, solar energy harvesting, and thermoelectrics.

Each year members of the Center, which include researchers from seven institutions across the United States, come together to discuss recent research discoveries and brainstorm new ideas to drive the field forward. Participants at this years meeting included representatives from ɫ��Ƶ��, NREL, The University of Arizona, Emory University, University of Kentucky, Georgia Institute of Technology, and Stanford University.

The two day meeting was a great opportunity for the community to build relationships across the different institutes, present their research, and develop new ideas for future directions.

02/11/2025

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Catalyzing the Sustainable Decomposition of PFAS Forever Chemicals

Daniel Morton — Sat, 21 Dec 2024 00:30:44 +0000

Catalyzing the Sustainable Decomposition of PFAS Forever Chemicals Daniel Morton Fri, 12/20/2024 - 17:30

Daniel Morton

RASEI Fellow Niels Damrauer is part of a collaborative team that have developed a new light-driven C-F activation reaction, one that has the potential to help dismantle PFAS ‘forever chemicals’

Find out more

Read the Article

Highlight in The Conversation

C&EN Highlight

Colorado Arts and Science Magazine Highlight

Perfluoroalkyl and polyfluoroalkyl substances, or PFAS, are synthetic compounds that have found widespread use in consumer products and industrial applications. Their water and grease resistant properties have been part of their attraction in their applications, but these are also the reason that they are now found practically everywhere in the environment, they are very difficult to decompose.

While many chemicals will decompose relatively quickly, studies have shown that PFAS are expected to stick around for up to 1000 years. While this durability is great in something like firefighting foams or non-stick cookware, it is not great when these compounds get into the environment.

This new article, published in Nature in November of 2024, describes the work of a collaborative team of theoretical and experimental chemists, who have developed a new photochemical reaction that could hold promise of speeding up the decomposition of PFAS. A recent highlight of this work, written by the graduate student and postdoctoral fellows who did the research, appeared in The Conversation.

Using a photocatalyst, that absorbs light to speed up a reaction, the researchers were able to ‘activate’ one of the carbon-fluorine bonds, one of the strongest bonds in organic chemistry. The photocatalyst absorbs light, transfers electrons to the fluorine containing molecules, which then breaks down the sturdy carbon-fluorine bond.

While this doesn’t decompose the whole molecule, it is essentially like finding a chink in the armor, it opens the door to degradation of the PFAS to harmless smaller molecules.

This study demonstrated this process on a small scale, and the researchers are looking at how to optimize this reaction so it is more robust and can be done on larger scales. This work is part of a National Science Foundation funded Center for Chemical Innovation called SuPRCat, a research community that will be looking at this challenge, among others.

If it is possible to break down these forever chemicals, it will help prevent these environmental pollutants being in our soil, rivers, and drinking water. Excited to see the next steps from the team!

December 2024

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2024 VinFuture Sci-Tech Week and Awards

Daniel Morton — Sat, 07 Dec 2024 19:18:25 +0000

2024 VinFuture Sci-Tech Week and Awards Daniel Morton Sat, 12/07/2024 - 12:18

Daniel Morton

Find out more

RASEI Director Seth Marder spoke at the 2024 VinFuture Sci-Tech Week and Awards Ceremony, where ɫ��Ƶ�� Colleague Kristi Anseth was honored with the Special Prize for Women Innovators Award.

December 2024 – This week in Hanoi, Vietnam, the VinFuture Foundation hosted the 2024 Sci-Tech week and award Ceremony. This series of world-class events bring together leading scientists and experts from across a range of critical scientific fields, including materials science, artificial intelligence, air pollution and environmental studies. The capstone of the week is the Award Ceremony, recognizing scientists for their groundbreaking achievements that have significant societal impact.

RASEI Director Seth Marder was an invited keynote speaker in the Materials for a Sustainable Future session. ɫ��Ƶ�� colleague Kristi Anseth received the 2024 Women Innovators Award, recognized for the advancement in design of polymeric biomaterials and methods for biomedical applications. Kristi is a pioneer in the development of biomaterial cell culture systems, critical components in the regulation of tissue development, maintenance and regeneration. Her team has designed new materials that can be engineered for tissue regeneration and accelerate healing of disease states. This provides a foundation for the study of 4-D biology in vitro with responsive and synthetic biomaterials, regenerating tissues across the human body.

Congratulations Kristi!

December 2024

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