Luca

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, 91��), Seth Marder (Chemistry and Chemical & Biological Engineering, 91��), Stephen Barlow (RASEI, 91��) 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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Quinone-annulated imidazolium salts as dual electrolyte-sorbents for electrochemical capture of carbon dioxide

Daniel Morton — Thu, 15 May 2025 21:35:09 +0000

Quinone-annulated imidazolium salts as dual electrolyte-sorbents for electrochemical capture of carbon dioxide Daniel Morton Thu, 05/15/2025 - 15:35

JOURNAL OF MATERIALS CHEMISTRY A, 2025, 13, 23, 17842-17851

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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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POSE Fall 2024 Kickoff Workshop

Daniel Morton — Mon, 07 Oct 2024 22:43:24 +0000

POSE Fall 2024 Kickoff Workshop Daniel Morton Mon, 10/07/2024 - 16:43

Daniel Morton

In early October of 2024, RASEI hosted the kickoff workshop for POSE, a new community being brought together to address some of the most critical challenges we face to do with plastics and polymers.

Polymer Solutions for the Environment, or POSE, seeks to establish a Center that will bring together expertise around the development of a circular polymer economy.

Plastics and polymers are critical materials in the modern age, forming the building blocks of everything from electronics to packaging, but this versatility comes with a cost, namely the waste and infiltration of the environment by microplastics.

This workshop brought together thought leaders in the polymer sector, from a cross section of academic, national lab and industrial organizations. The goal was to explore how best the POSE community can build a program that complements existing efforts in the field to drive the science and policy forward.

Three areas of focus were discussed, including the development of a circular polymer economy, the development of polymers that are needed for a just clean energy transition, and the integration of the science and technology research with policy, economics and social sciences.

It was a great meeting with more than 60 participants who came together to discuss ideas, present their research and approaches, and help shape the goals and directions of this nascent community.

10/07/2024

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Polymer Solutions for the Environment Fall 2024 Workshop

Anonymous — Mon, 09 Sep 2024 15:52:40 +0000

Polymer Solutions for the Environment Fall 2024 Workshop Anonymous (not verified) Mon, 09/09/2024 - 09:52

Polymer Solutions for the Environment Fall 2024 Workshop

Monday October 7, 2024 | 9:00 AM - 4:30 PM

91��, East Campus, SEEC Building C120

Join us at this kick-off workshop for the Polymer Solutions for the Environment initiative. This will be held at 91��, on the East Campus in the SEEC Building, Room C120 on Monday October 7, 2024. This one-day workshop brings together key collaborators and stakeholders from across the region, with a focus on discussing and developing a roadmap for POSE. Talks will have a spotlight on how POSE can join and amplify the existing regional community of researchers in tackling Colorado's most pressing sustainability challenges and exploring the role of polymer science in addressing these issues. We plan to define the goals, milestones, and target research areas for POSE.

10/07/2024

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New Frontiers Grant Program Successes for RASEI Fellows

Anonymous — Wed, 08 May 2024 20:48:10 +0000

New Frontiers Grant Program Successes for RASEI Fellows Anonymous (not verified) Wed, 05/08/2024 - 14:48

Daniel Morton

The 91�� New Frontiers Grant Program was launched in 2024. The program is designed to foster visionary groundbreaking, interdisciplinary research projects that have potential for high impact. This could include significant advances in knowledge, problem-solving or innovation that can build to new paradigms of understanding.

New Frontiers Grant Program

2024 Award Announcement

A central column of this program is to stimulate the development of new strengths at 91��, driven by researchers thinking across disciplines and developing methods to work together to tackle complex and impactful research challenges.

Twenty-six teams submitted collaborative proposals were submitted to this program earlier this year and four projects were selected as winners of planning grants, two of which involved RASEI Fellows.

New Frontiers in Bio-Integrated Organic Computing & Low-Energy Innovative Carbon-based Manufacturing, or BIO-CLIC, led by RASEI Fellow Jeff Cameron and engaging a team across four 91�� departments and collaborators from NREL, will explore challenges in computational efficiency by investigating unconventional computing approaches that employ renewable sources and carbon fixation processes.

Polymers for a Sustainable Earth, or POSE, led by Wei Zhang from the Department of Chemistry and involving RASEI Fellows Dan Kaffine, Kat Knauer, Oana Luca, Seth Marder, Srinivas Parinandi, Mike Toney, and Terri Walters, brings together collaborators from six 91�� departments and NREL. POSE will foster a community to facilitate extramural research and funding at a scale to effectively address the issue of plastic pollution and new, sustainable methods to synthesize, reuse, and recycle polymers.

The four teams were chosen following 14 in-person pitches, where the teams outlined how their proposed work addresses important societal problems through adopting collaborative interdisciplinary approaches. The four teams will now use the next year to advance their proposals, build out the team and conduct initial investigations on how to take things forward. The teams will then compete for the single Launch Phase Grant of $200k, which will be awarded in June 2025.

Congratulations to the teams! We look forward to seeing your progress over the next year!

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Beyond n-dopants for organic semiconductors: use of bibenzo[d]imidazoles in UV-promoted dehalogenation reactions of organic halides

Anonymous — Thu, 14 Dec 2023 07:00:00 +0000

Beyond n-dopants for organic semiconductors: use of bibenzo[d]imidazoles in UV-promoted dehalogenation reactions of organic halides Anonymous (not verified) Thu, 12/14/2023 - 00:00

BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY, 2023, 19, 1912-1922

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Five ways 91�� researchers are working to address climate change

Anonymous — Tue, 28 Nov 2023 07:00:00 +0000

Five ways 91�� researchers are working to address climate change Anonymous (not verified) Tue, 11/28/2023 - 00:00

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Experts on COP28

Anonymous — Tue, 28 Nov 2023 07:00:00 +0000

Experts on COP28 Anonymous (not verified) Tue, 11/28/2023 - 00:00

RASEI Community members are on hand to comment and connect over COP28

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The future of recycling could one day mean dissolving plastic with electricity

Anonymous — Mon, 03 Jul 2023 06:00:00 +0000

The future of recycling could one day mean dissolving plastic with electricity Anonymous (not verified) Mon, 07/03/2023 - 00:00

Daniel Morton

Plastics have proven to be a revolutionary class of materials, that are durable, lightweight, water resistant and relatively inexpensive and easy to manufacture. It is hard to think of a modern piece of technology that doesn’t include some plastic components, from electronics to plastic bottles.

The same properties that make plastics useful are also behind the creation of a global waste crisis.

Media Highlights:

Energy & Environment Leader

Materials Today

Plastics are polymers, long chains of molecules connecting together repeating links called monomers. By changing the chemical structure of the monomers, and the way in which they are connected together, the properties of the plastic can be engineered.

The majority of plastics are durable, which is great for an application (no one wants a leaky bottle of water), but not so great when you need to dispose of the application. Waste plastics can litter the environment for centuries. Larger pieces of plastic, such as bags, straws, bottles, packaging and many everyday objects, are called macroplastics. When present in the environment these pose a threat to wildlife through entanglement or consumption. The problem doesn’t stop there. Macroplastics can break down into smaller and smaller pieces, forming microplastics (<5 mm long), that are becoming increasingly ubiquitous, now found as pollutants in every part of our environment. While these plastics are being broken down into smaller pieces, on the chemical level the strong polymer chains remain strong, making them very hard to get rid of. It is estimated that on our current trajectory, by 2050 there could be more plastic in the ocean than fish (by weight; Ellen MacArthur Foundation, 2016).

Due to a combination of the strength of plastics and poor waste management systems, it is estimated that only 15 % of plastic waste is recycled. Most of the population operates on a linear economy model, a so-called “take-make-discard”, where raw materials are refined, used to manufacture products, which are then simply disposed of at the end of life. It is imperative that we move to a circular economy model for plastic use and recycling, and this work, by two teams of RASEI researchers, provides a step toward this transition.

Current plastic recycling methods are not up to the task. The most globally used method is called mechanical recycling. Plastics, which have been collected and separated, are mechanically broken down through a combination of chopping and grinding to produce a powder that is then melted and extruded into pellets ready for reheating and remolding. This process can only be done a few times. Melting can be destructive to the chemical structure and eventually, through repeated cycles, the plastic loses its strength.

RASEI Fellow Oana Luca and her team, in collaboration with the group of RASEI Fellow Seth Marder, have demonstrated an electrochemical approach to chemical recycling of polyethylene terephthalate (PET) plastics. PET is one of the most common plastics, used in clothing, food containers and bottles. In chemical recycling the work is done at the molecular level. By applying an electric current to a solution of the plastic and a redox catalyst (a molecule capable of capturing and then donating an electron), the polymer chain is broken in a selective manner to produce the original starting materials. Instead of getting a random mixture of chemical structures, as you would through heating in mechanical recycling, you get clean starting materials, which, after separation, can be used to produce new plastics. Using this technique there is no limit to the number of times plastics could be recycled. With the amount of plastic waste in the world, you would never have to use new starting materials!

While this approach holds great promise, there is a lot of work still to be done. The process shown in the lab could break down about 40 milligrams (about 1 /500 of a 16 Oz PET bottle), over a period of several hours.

“Although this is a great start, we believe that lots of work needs to be done to optimize the process as well as scale it up so it can eventually be applied on an industrial scale” said Phuc Pham, a doctoral student in the Luca Group.

The generality of this electrochemical approach offers an exciting opportunity. Different types of plastics could be put into the same chemical reactor and broken down into their respective starting materials, which could then be separated, which could significantly mitigate and streamline some of the waste collection and management issues.

“There are so many polymers and materials out there that people aren’t recycling at all. They’re not being collected. This is the beginning of many, many different kinds of chemistries” said Oana Luca.

This collaborative team, led by RASEI Fellow Oana Luca and including RASEI Director Seth Marder describes new approaches to PET recycling.

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Luca

Electricity, Air, and Plastic Recycling

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Quinone-annulated imidazolium salts as dual electrolyte-sorbents for electrochemical capture of carbon dioxide

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Air-Enabled Electricity-Driven Depolymerization of Polyesters

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POSE Fall 2024 Kickoff Workshop

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Polymer Solutions for the Environment Fall 2024 Workshop

Polymer Solutions for the Environment Fall 2024 Workshop

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New Frontiers Grant Program Successes for RASEI Fellows

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Beyond n-dopants for organic semiconductors: use of bibenzo[d]imidazoles in UV-promoted dehalogenation reactions of organic halides

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Five ways 91������ researchers are working to address climate change

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Experts on COP28

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The future of recycling could one day mean dissolving plastic with electricity

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Five ways 91�� researchers are working to address climate change