Tackling the Plastics Problem

Tackling the Plastics Problem

Collaborative project aims to find sustainable ways to create, destroy plastics

Despite the society-changing improvements that plastic materials have brought to humanity, there’s no question that they also present us with new challenges regarding what to do with the large amounts of plastic waste we generate, from the oil-based chemicals used to create products to the microplastics found everywhere after plastics breakdown in the environment.

Finding a solution to plastics pollution that will work in the lab and in the real world will take a diverse team of innovative individuals with expertise that transcends the incredible talent found at the University of Delaware. That’s why researchers from UD’s College of Engineering and Biden School of Public Policy and Administration are joining forces with experts at the University of Kansas and Pittsburg State University.

“The practices by which society works now are really not sustainable,” said Raul Lobo, Claire D. LeClaire Professor of Chemical Engineering and associate department chair in UD’s Department of Chemical and Biomolecular Engineering, who is leading the research effort for UD. “We need materials that minimize our dependency on fossil fuels and that allow consumers to recycle plastic products efficiently and with ease.To this end, the UD-KU team will develop new molecules that can be used to make a new generation of environmentally friendly plastics.”

Raul Lobo, Claire D. LeClaire Professor of Chemical Engineering and associate department chair in UD’s Department of Chemical and Biomolecular Engineering, is leading the research effort for UD in collaboration with experts at the University of Kansas and Pittsburg State University to find sustainable ways to create new plastics and more efficiently reuse them.

The National Science Foundation’s Experimental Program to Stimulate Competitive Research has awarded the group $4 million in funding to do just that. About $1.4 million of that funding will go to UD to support this vast research effort to develop processes to transform “biomass,” such as agricultural byproducts, into commercially viable plastics materials and to chemically deconstruct such plastics effectively and efficiently so that they can be recycled and reused.

UD faculty members on the team include Professor Hui Fang with the Department of Electrical and Computer Engineering, Professor Kalim Shah with the Biden School and Department of Chemical and Biomolecular Engineering Professors Marianthi Ierapetritou, Lobo, Marat Orazov and Dionisios Vlachos.

Lobo, who also holds a joint professorship in the Department of Materials Science and Engineering, said the project will focus on developing polymers that behave like polyethylene terephthalate, or PET, a very common type of plastic found in consumer products such as water bottles, fleece and food-wrapping film. A polymer is a very long molecule, such as proteins, starch or DNA, that is built of repeated building units, like the adenine (A), guanine (G), cytosine (C) and thymine (T) in DNA molecules. Different polymers form by knitting together different building units. Once they are sufficiently long, they can be easily melted, shaped or molded, and solidify upon cooling

“We have ideas of polymers we think will make materials that are better than PET in a number of ways,” Lobo hinted. “Now, we have to prove it.”

From Biomass to Building Blocks

The goal is not only to find new materials with good and useful properties, but to do so using molecules with building blocks that come from biomass (and not fossil fuels like oil) and that are designed to be recyclable.

“We’re trying to make this society more sustainable by developing technology that has the potential to be practical,” Lobo said. “The material we’re trying to make … looks like the plastics we use today, but comes from biomass.”

This graphic illustrates the flow of a “circular economy,” as opposed to the “linear economy” of the U.S. In a circular economy, products are produced, consumed and reused so that there is little or no waste leftover during any of those processes.

For example, plants also produce sugars with fewer carbons than the sugar that we eat, and those sugars and their derivatives could be used as building blocks for plastics. The material has to be stable just enough, and strong enough, to hold up in another life as, say, a plastic bag. By focusing on biomass that’s not edible and not toxic — think of stalks from corn or leftover parts from harvested sugar cane — researchers will try to prepare new building blocks for plastics such that they don’t compete with food sources, do not depend on fossil fuels and can be easily assembled and reassembled.

Then these engineers must figure out how to translate the science into actual societal benefit. That means also exploring the policy and economic elements associated with shifting the foundational building blocks of a product used in almost everything in our daily lives.

The practical implications of this work will certainly relate to cost. Six decades of experience making PET and using it in multiple products means six decades of being able to find cost efficiencies along the way. It will still take some time for any new building blocks that could replace PET, even if they are superior in performance and for the environment, to find all possible efficiencies and cost savings.

Over the next four years, up to five UD graduate students will play a role in this interdisciplinary research, from the machine learning that will be used to explore existing research literature and gaps in knowledge, to the chemistry of the components, to the economics of their application and recycling.

“There’s a vast amount of information there,” said Hui Fang, an associate professor with the Department of Electrical and Computer Engineering. “We’re trying to develop a machine learning-based technique that can first extract information automatically from the literature and then allow the researchers to see what’s missing.”

From Wastefulness to Sustainability

With so much waste in the world — up to one-third of the food resources produced are actually wasted — it would be incredibly beneficial to find ways to reuse those tossed corn husks or the leftover fibers from sugar cane, particularly as we try to avoid 1.5 degrees Celsius of atmospheric warming due to greenhouse gas emissions. At the United Nations Climate Change Conference in Glasgow, experts emphasized that exceeding that level of warming will not only be catastrophic, but will be impossible if world nations cannot curb their reliance on fossil fuels.

The idea of a “circular economy,” in which products are produced, consumed and reused — as opposed to the “linear” way the world currently produces, consumes and trashes most products — could literally be that change the world needs. From the molecular beginnings of plastic products, energy is used and waste created. But is it possible to reduce this amount of energy and could the waste be reused in another production process?

Dionisios Vlachos, Unidel Dan Rich Chair in Energy Professor of Chemical and Biomolecular Engineering, director of the Catalysis Center for Energy Innovation and director of the Delaware Energy Institute, is exploring how to make new building blocks for plastics from current waste streams.

“We’re thinking about how we can take the waste stream and make new building blocks,” said Dionisios Vlachos, Unidel Dan Rich Chair in Energy Professor of Chemical and Biomolecular Engineering, director of the Catalysis Center for Energy Innovation and director of the Delaware Energy Institute. “This is a global issue.”

Today, most plastics (and many of the other products we consume daily) are created from petrochemicals. Most plastics are not easily recycled because once they’re broken down into their original pieces, they are difficult to put back together again and so they ultimately end up as waste. UD’s investigators are in pursuit of novel chemicals that can be easily manufactured from biomass and that not only make outstanding plastics, but also could, with little effort, be transformed into raw materials for new plastic products.

“If we don’t take action today, things will be really bad in the future,” Vlachos said. “There are many waste streams with multiple societal health problems. They have to be addressed at a global scale. If we’re making renewable plastics, it would be great, but it’s just part of the story.”

A Holistic View

While some on the team will focus on the chemical engineering of the molecules themselves, Ierapetritou and her team will be analyzing those new materials for their potential environmental impacts, economic costs and whether the new product would be practically scalable from a small lab to a commercialized solution.

In this project, Bob and Jane Gore Centennial Chair of Chemical and Biomolecular Engineering Marianthi Ierapetritou and her team will be analyze proposed new materials for biorenewable plastics for potential environmental impacts, economic costs and feasibility.

“Of course, this goes back to changing the culture of people or introducing different policies, which is one of the things we’re hoping to investigate,” said Ierapetritou, who is the Bob and Jane Gore Centennial Chair of Chemical and Biomolecular Engineering at UD. “But you need policies, you need incentives to make the change that needs to be made.”

What they’re aiming to create may be expensive — possibly too expensive to compete without incentives. But even if some of the new material was used in plastics production, it could still help reduce the pollution associated with creating a product made with 5% or 10% biomass-sourced plastic, said Lobo.

“Our scientific and engineering folks say they can do this in the lab, and they can scale it up. But where is the acceptance or adoption of it?” said Kalim Shah, an assistant professor at the Biden School of Public Policy who will be exploring the economic and environmental implications of a substitute for plastics and its potential in real-world markets.

“I think there’s a real awareness now of linking the disciplines that we’re very well known for at UD — chemistry and chemical engineering — to the policy and macroeconomic business aspects of the problem,” he said. “I’m really happy to have colleagues that are willing to include my perspective and take a multidisciplinary approach to us to move forward together.”

Kalim Shah, an assistant professor at the Biden School of Public Policy, will look at the economic and environmental implications of a proposed biorenewable substitutes for plastics.

If they find the solutions they believe exist, it would still take years before a plant capable of making thousands of tons of polymers goes online. The biomass-sourced building blocks could also be a boon for farmers and companies that work with the agricultural products that could become future plastics.

There’s also the potential they could create something even better: a biosourced plastic that can last longer or require less material.

Their work will also closely examine how to deconstruct these new polymers so that it can be a truly recyclable product. Lobo said he had no doubt they could succeed on that front. But whatever they uncover, they will publicize their findings and make them available to other researchers.

“If we succeed, we might be able to reduce, to some degree, the quantity of plastics or the amount of oil we consume,” Lobo said. “There are chemical reasons why some polymers have these good properties but others don’t. Based on that information, we’re going to eventually be able to provide better products for society. That’s what engineers do.”

 Photos by Evan Krape, Lane McLaughlin and iStock | Image courtesy of Dionisios Vlachos | 

Interdisciplinary Problem Solving

Interdisciplinary Problem Solving

Computing, engineering and polymer sciences converge in new NSF doctoral traineeship

Big-name chemical companies like DuPont and W.L. Gore have complex materials problems to solve. The trouble is they’re in need of well-rounded researchers to find the solutions they’ve been looking for, ideally highly skilled scientists with more than one area of expertise—like someone fluent in both materials engineering and computer science.

Recognizing that real-world need, award-winning UD Professor Arthi Jayaraman has created a collaborative, cross-disciplinary traineeship that will provide selected doctoral students from the University of Delaware and Delaware State University with the technical and professional training they need to thrive in their careers after graduation.

Anshuman Razdan

“That’s part of our mission, it’s at the core of what we do: Prepare our students, whether it’s for a life after as faculty or in national laboratories or industry,” said Anshuman (“A.R.”) Razdan, associate vice president of research development in UD’s Research Office. Jayaraman credited Razdan, along with Graduate College Dean Louis Rossi, for playing key roles in bringing her idea for this traineeship program to life.

“This is not a Ph.D. program by itself, but is designed to make the graduate student experience better,” Razdan said. “It’s an interdisciplinary collision, in a positive sense, and builds on extensive UD investment and success in the data sciences.”

The new National Science Foundation-funded Research Traineeship “Computing and Data Science Training for Materials Innovation, Discovery, AnalyticS” (NRT-MIDAS) will teach doctoral students in computer and information sciences, electrical and computing engineering, chemical engineering, materials science and engineering, biomedical engineering and chemistry programs how to use high-performance computing and data science to lead to new discoveries and innovations in the field of polymers.

NSF has awarded Jayaraman a nearly $3 million grant to support this traineeship over the next five years. Jayaraman, Centennial Term Professor in UD’s College of Engineering’s department of Chemical and Biomolecular Engineering with a joint appointment in Materials Science and Engineering, will serve as director of this traineeship program. This traineeship will work with 50 to 100 UD and DSU doctoral students, some of whom will receive financial support for two years through this NSF grant. International students will also be able to apply to the traineeship program and some selected students may receive one semester of financial support from the College of Engineering.

The program is slated to admit its first cohort of new UD and Delaware State University graduate students from one of the six specified programs in winter 2022. Applications are due by Tuesday, Nov. 30, and selections will be made by Wednesday, Dec. 15.

Besides the interdisciplinary technical skills, trainees will also learn the essential professional skills that every employer wants to see in their employees: Researchers who know how to interact with team members from diverse backgrounds and know the importance of adaptable science communication both in the laboratory and to the broader community.

“All of the training elements were strategically selected: The technical training elements, applying computing and data science to polymer problems in the real world, combined with professional training elements where trainees work in teams with people who aren’t from the same discipline, learning to communicate, and going above and beyond to explain their work to the other person,” Jayaraman said. “Essentially this MIDAS traineeship is that extra, customized, all-rounded training layer we’re putting on top of what these doctoral students receive in their own graduate programs.”

In this photo taken before the coronavirus pandemic necessitated the wearing of masks and distancing in classrooms, Prof. Arthi Jayaraman speaks with students in her chemical engineering class.

The diverse NRT core faculty team facilitating this collaborative training environment were also strategically selected, and were chosen because of their accomplishments and expertise in one or two of the relevant disciplines. For example, Prof. Laure Kayser with the Department of Materials Science and Engineering has expertise in polymer materials for organic electronics, Prof. Austin Brockmeier with the Data Science Institute and the Department of Electrical and Computer Engineering has expertise in data science applied to a variety of domain sciences, while Prof. Sunita Chandrasekaran with the Department of Computer and Information Sciences brings her expertise in high-performance computing.

On the forefront of solutions

Since polymers are used in everything from food packaging and paints to electronics and medical settings, companies are constantly searching for the latest and greatest materials for, say, an airplane body or COVID-19 vaccine delivery. That means both industry and academia are often pursuing ways to optimize polymers, turning to chemistry, materials science and engineering for solutions.

By offering professional cross-training in those disciplines as well as computer science and data science, Jayaraman hopes trainees will learn how to let the machines handle the optimization and avoid the tedious trial and error that would usually come with running all possible experiments in the lab. By combining disciplines, they can use computing, modeling and artificial intelligence to save the chemicals, time and effort that extensive laboratory experiments typically need.

“If you just did experiments in a lab, you’d test one chemical and ask, ‘How does it perform? How does it behave?’ and then move to the next chemical and repeat the process. This is trial and error,” Jayaraman said. “Companies often want to find faster and cheaper ways to explore different chemicals and get to the better-performing product.”

Joshua Enszer

That’s why Jayaraman made sure the program is partnering with companies searching for such solutions. In addition to DuPont and W.L. Gore, the traineeship has also established industry partnerships with Argonne National Laboratory, Brookhaven National Laboratory, Merck & Co. and Procter & Gamble, with more companies expected to join in the coming months and years.

An “NRT-Hackathon” course that is being designed for the traineeship program, after trainees complete core classes and right before they explore internships, will collect real-world problems from participating companies and turn them over to small teams of students to explore and solve with computing and data science tools over the course of a semester.

“Each problem will be a semester-long problem, and students from different disciplines in each team will have to teach each other what it means,” Jayaraman said, noting that a computer sciences student will need to learn the specific properties of a chemical, while the chemical engineer sharing that information will have to learn about the computing methods their computer science colleague is using to develop data-based solutions.

Not only will the training benefit students, but it will also serve existing and future industries by preparing a well-rounded workforce and also finding ways to solve real problems by replacing trial-and-error based experiments with computing-based approaches.

“It more than bridges the gap, it has a serious economic impact,” Razdan said, noting that the program could also help participating students decide whether a life in industry or academia is better for them.

In addition to these custom interdisciplinary courses that emphasize the importance of clear communication across disciplines, trainees will also complete their regular graduate work, and benefit from a secondary NRT-MIDAS-specific adviser.

“The way a chemical engineer talks and the way a computer scientist talks is not the same,” Jayaraman said. “We want to sharpen those professional skills, especially cross-disciplinary communications, by working in team environments with different backgrounds, both culturally and technically.”

An academic approach

Not all of the talented graduate students that will be selected for this traineeship will pursue industry careers; some may want to work in academia, where they could foster this comprehensive approach in their own future classrooms. Those pedagogically minded students will hone the teaching and communications skills they’ll need, but would otherwise not be included in their normal graduate programs. With this motivation, Jayaraman recruited a pedagogical expert into the NRT-MIDAS core faculty team.

Cathy Wu

“What we’re trying to do here is fill in a big need to have people who are better teachers from the start,” said Joshua Enszer, a chemical and biomolecular engineering associate professor and member of the NRT core faculty team. The NRT-MIDAS teaching fellowship builds off a program underway in the Department of Chemical and Biomolecular Engineering, where a handful of fellows work with faculty to actually implement a course during their graduate studies, he said.

“Because we’re bringing together these very important and very related areas, we’re working on helping improve communication on both sides,” Enszer said. “Bringing that together and then teaching everyone together is a really exciting opportunity. I think it’s going to help prepare this generation of graduate students for a variety of potential different careers.”

A diverse NRT-MIDAS core faculty team of nine faculty members, including Jayaraman, will provide technical and research training and mentoring. An independent advisory council, made up of six international experts from academia, national laboratories and industry, will offer their perspectives and recommendations in order to strengthen this interdisciplinary traineeship.

“UD really is an excellent environment for doing team science,” said Prof. Cathy Wu, an NRT-MIDAS core faculty member and Unidel Edward G. Jefferson Chair in Engineering and Computer Science, director of the Center for Bioinformatics and Computational Biology, director of the Data Science Institute and director of the Protein Information Resource. “This is just a great example of how Arthi (Jayaraman) has brought such an excellent, diverse team together for this particular training grant. But if we look around UD, this kind of very collaborative effort is happening with many different initiatives. I think team science, this kind of very inclusive environment, really is a signature of what we do at UD.”

Jayaraman and others at UD hope this training continues beyond the recently awarded grant.

“I tell faculty it’s like building a building,” Razdan said. “We want the faculty focused on building the building, constructing the idea. All of us, we’re here to support Arthi with scaffolding so she has everything she needs to imagine and execute the ideas that can only come from her. We’re very, very happy to be that scaffolding for her.”

 Photos by Evan Krape | 

Renewable Energy Grants

Renewable Energy Grants

UD’s Shafarman, Firestone lead Department of Energy funded projects

University of Delaware researchers will soon begin work on two new renewable energy-related projects, backed by about $4 million in new U.S. Department of Energy grants as well as cost-sharing grants from UD and several partners.

Jeremy Firestone, professor in the College of Earth, Ocean and Environment, and William Shafarman, director of the Institute of Energy Conversion and professor of materials science and engineering, are the principal investigators on the projects, which are getting about $2 million each.

The projects have wide-ranging goals, from advancing renewable energy technology to evaluating barriers to clean-energy technology and addressing the needs of industry. The projects demonstrate again UD’s longtime leadership in energy technology — especially photovoltaics, electricity, wind, fuel cells and electric vehicles.

Firestone, director of UD’s Center for Research in Wind (CReW), will explore the decision-making process of those who adopt the use of solar energy systems and/or electric vehicles. He and his team will look at primary influences on those choices, including incentives and barriers, and develop the nation’s first large database of those factors. The goal is to identify non-technological barriers to clean-energy co-adoption. Support for this work comes from the Energy Department’s Solar Energy Technologies Office.

Shafarman and the IEC team will work to show how a new process recently developed by the IEC’s Brian McCandless will not only improve the efficiency of solar panels but also simplify the manufacturing process for industry, allowing firms to make their solar products both better and less expensive. Support for this work comes from the Energy Department’s Office of Energy Efficiency and Renewable Energy.

Adopting renewable energy

Firestone has done extensive research on large-scale energy infrastructure and the social dimensions of renewable energy technology. This new study, he said, is both a continuation and a departure from that work.

“Although both threads focus on social dimensions of technology, in my prior work I examined reactions to renewable energy infrastructure, while the present research will look at motivations for and barriers to a personal decision to put solar panels on one’s roof or buy an electric vehicle or both,” he said.

Professor Jeremy Firestone of UD’s School of Marine Science and Policy stands in the driveway of a house with solar panels and an electric vehicle.

It is a natural outgrowth of CReW’s focus on electric vehicles and vehicle-to-grid (V2G) technology, he said.

Researchers will interview those who have bought electric vehicles and/or rooftop solar and develop surveys and control experiments to explore their motivations. The first survey will look at differences between four groups of people: Those who own both electric vehicles and solar panels, those who have purchased only an electric vehicle, those who only have solar panels, and those who have not yet purchased either.

Consumers weigh many factors when considering what to buy and this study will draw on expertise in cognitive and social psychology and behavioral economics. One of the goals of the research is to identify consumer characteristics and patterns of decision-making that lead them toward or away from purchase of rooftop solar or electric vehicles or both.

“Individuals may be influenced by the presence of rooftop solar panels on the homes of their neighbors, views about the return on investment in an electric vehicle or personal and social norms related to a clean-energy future,” Firestone said.

Context may be a key factor. A person may own an electric vehicle, but not have solar panels on the house — not out of opposition to such systems, but because the house is on a wooded lot or they rent rather than own the house. Conversely, a person may have solar panels on the roof but not have off-street parking that could accommodate electric-vehicle charging.

“It’s a change in focus,” Firestone said. “The magnitude of energy technology is changing, going from utility-scale generation to personal generation and personal choices on vehicles. The change is more about the scale of the technology than the technology itself, but it’s all part of energy transition.”

In the second survey, researchers will evaluate low-cost interventions and incentives and whether they increase the probability that a person with solar panels would also purchase or lease an electric vehicle, and vice versa. One of Firestone’s colleagues, George Parsons, Unidel E.I. du Pont Professor of Marine Science and Policy, will lead this aspect of the research.

Collaborating researchers include UD’s Steven Hegedus, senior scientist at IEC and professor of electrical and computer engineering, along with partners at the University of California, Davis, the University of Chicago, Lawrence Berkeley National Laboratory and a consultant with V2G expertise.

Improving solar manufacturing process

The IEC project was primarily developed by Brian McCandless, who learned that he had won the new grant the day before he retired from UD.

This photo was taken in 2018, before the coronavirus pandemic necessitated wearing masks and social distancing. Before retiring, UD scientist Brian McCandless (right) worked as an associate scientist with the Institute of Energy Conversion (IEC). McCandless applied for the recent Department of Energy grant that Bill Shafarman’s team will use to study ways to improve manufacturing of solar panels. In this photo, McCandless is working with Wayne A. Buchanan, who was a research associate at the IEC.

Shafarman now is the principal investigator on the project, “but all the credit for the concept goes to Brian,” Shafarman said. “It is his vision and brainchild and it’s great — an exciting new project.”

Working with Shafarman at IEC will be Associate Scientist Ujjwal Das and Research Associate Shannon Fields. Other partners and subcontractors include Anderson Janotti, associate professor in materials science and engineering, and researchers at Drexel University, Ohio State University and the National Renewable Energy Laboratory.

The grant also will support up to three students, all in materials science, Shafarman said.

In 2018, McCandless used the UD-patented Vapor Transport Deposition System he developed to show how adjusting the properties of thin-film photovoltaics produced smoother sailing for the electrons traveling through solar cells. That opened the door to increased efficiency and reduced cost.

“It was very good science and now we’re trying to make it good technology, while also diving in to understand the underlying fundamentals of the materials and the solar cells we make from them,” Shafarman said.

The advance is compatible with existing commercial processes used by the nation’s largest solar manufacturers, he said.

Thin-film technology is a staple at IEC, which was established in 1972 and is considered the world’s longest continuously operating solar research center. Thin films have advantages over the more commonly used solar wafers, including higher flexibility, lighter weight and simpler manufacturing.

The new process could increase the efficiency of thin films to 25%, a significant stride from the present highwater mark of 22.1%.

Solar Energy Technologies Office 

The U.S. Department of Energy Solar Energy Technologies Office supports early-stage research and development to improve the affordability, performance and value of solar technologies on the grid.

Office of Energy Efficiency and Renewable Energy

The mission of EERE is to create and sustain American leadership in the transition to a global clean energy economy.

| Photos by Kathy F. Atkinson and Evan Krape |