ChemE NEWS SPRING 2021
CHEMICAL & PETROLEUM ENGINEERING
Annual Publication of the University of Pittsburgh Swanson School of Engineering
Building a Circular Chemical Economy
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arbon dioxide is essential to plant and animal life, but in excess it negatively impacts the environment by absorbing and radiating heat in the atmosphere, contributing to global warming. But what if we could recycle carbon dioxide by converting it into useful fuels and chemicals? James McKone is tackling this idea and was selected as a Beckman Young Investigator (BYI) by the Arnold & Mabel Beckman Foundation for this work. “Over the last several decades, the cost of renewable electricity has dramatically decreased to the point where building a new solar or wind farm is, in many cases, more economical than continuing to run a coal-fired power plant,” said McKone, assistant professor of chemical engineering. “This is incredibly exciting because it means we can start to imagine what it would look like to power our whole society with carbon-free resources,” he said. Consider chemical manufacturing – the industry that produces most of the stuff that we use every day. The dangerous by-products and waste created by this industry adds to the massive global pollution problem – from the atmosphere to the depths of the ocean, and from backyards to beaches. According to McKone, simply improving renewable electricity is not enough to mitigate our
climate impact if we do not also rethink the way we make things like plastic, steel, and textiles. He received funding from the BYI program to develop new catalysts and chemical reactors that can recycle carbon dioxide and other chemical wastes back into useful fuels and raw materials. “We ultimately want to build a circular chemical economy – a sustainable approach to chemical manufacturing where every molecule that comes out of a smokestack or a tailpipe is captured and reused hundreds or thousands of times instead of being discarded as waste,” said McKone. His team will make two major adaptations to current industrial catalysts. Rather than heat, they will use electricity to drive chemical reactions so that they can use renewable resources as the main energy input. They will also mimic the behavior of biological enzymes to improve the efficiency of chemical reactions by designing specific catalytic units, called active sites, to perform each individual step of the complex chemical reactions. “Getting these catalysts to work is an incredible challenge,” said McKone. “To meet that challenge, we are developing new experimental capabilities that will allow us to measure and manipulate catalyst materials with atomic-scale precision.” The BYI program provides research support to the most promising young faculty members in
engineering.pitt.edu/chemical
the early stages of their academic careers in the chemical and life sciences. It challenges researchers to pursue innovative and high-risk projects that seek to make significant scientific advancements and open up new avenues of research in science. McKone is only the second Pitt professor selected for this award in the history of the BYI program. The first was Steven Little, William Kepler Whiteford Endowed Professor and Chair of Chemical and Petroleum Engineering. Alex Deiters, professor of chemistry at Pitt, is a third BYI who received the award during his tenure at North Carolina State University.
Engineering for the Environment... Letter from the Chair Dear friends, colleagues, and alumni, After a year of challenges faced because of the COVID-19 pandemic, I am excited to share with you a trove of academic and research news from Pitt’s Department of Chemical and Petroleum Engineering. The personal and professional challenges we’ve each faced have been daunting, but we are finally seeing that proverbial corner-turn coming in the months ahead. From research shutdowns and restarts to adapting new teaching modalities while balancing a pandemic family life at home, our Pitt ChemE faculty truly have excelled. Some have found a new niche to solve global problems, while others have tailored their research to address viral threats like the coronavirus. And most importantly our students have not simply pivoted in these new learning conditions but have made their own impact in the classroom and lab, as well as among their peers. The national recognition gained by our Department continues to instill a sense of pride which I hope you share. Most especially please join me in congratulating Assistant Professor James McKone on winning the competitive and coveted Beckman Young Investigator Award. His research in electrochemistry, photochemistry, and materials design is playing a critical role in our school’s focus on sustainability and circular economies, and we applaud his success. On the academic front, the inimitable Professor Taryn Bayles was recognized by ASEE with its Lifetime Achievement Award. Nationally recognized for her impact on engineering pedagogy and a respected scholar in the field, Taryn has helped to reshape our undergraduate curriculum and engage students in greater hands-on learning and activities. This includes our award-winning ChemE-Car team which she advises. Her perspective on engineering education, engagement, and community impact is such a valuable resource for our department and school. There is much more for you to enjoy in this newsletter, and I encourage you to bookmark us at engineering.pitt.edu/chemical to keep up on the latest from the department. May we find our hopes growing in the months ahead and a near future where we can celebrate together in person. Sincerely,
Steven R. Little, PhD William Kepler Whiteford Professor and Department Chair
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Greener Catalysis
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latinum, rhodium, and other precious metals are used as catalysts that make modern life possible, from the catalytic converters in cars to the production of many useful chemicals. These metals are stable and strong, but they are a very limited and expensive resource. Data scientists have estimated that all the platinum ever mined in the world amasses to just about 9,800 metric tons, a volume that would fit within just three standard semi-truck trailers. That is why researchers around the world, including John Keith, R.K. Mellon Faculty Fellow in Energy and associate professor of chemical and petroleum engineering, are looking to nature for ways to use far more earth-abundant metals (EAMs), like iron, instead. “Humans have developed portfolios of rare metals that work in industrial catalysis, but nature has its own portfolios of biological enzymes that use complex combinations of EAMs,” said Keith. “When we decipher nature’s blueprints for catalysis based on EAMs, we can engineer new EAM-based catalysts to dramatically reduce the cost and environmental footprint of industrial processes needed for making materials, medicines, fuels and chemicals.” The U.S. Department of Energy brought together a team of international experts in catalysis, including Keith, to write an authoritative review to lay the groundwork for the discovery of cheaper, quicker and more sustainable catalysts. That review article was recently published in Science, one of the top-ranked scientific journals in the world. The article discusses the background, advances, and promising outlook of bio-inspired EAM catalysis. More research will be needed to better understand how industrial processes can be developed to run in less harsh conditions that EAM catalysts require. Keith is an expert in computational chemistry, which uses computer simulations of atoms rooted in the laws of quantum mechanics, and this field is considered a key to progress in EAM catalysis development. Researchers in the Keith Lab use computational chemistry to rapidly explore and deeply analyze hypothetical catalysts that otherwise are too slow or expensive to test in the lab.
Sustainable Chemistry at the Quantum Level
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eveloping catalysts for sustainable fuel and chemical production requires a kind of Goldilocks Effect – some catalysts are too ineffective while others are too uneconomical. Catalyst testing also takes a lot of time and resources. New breakthroughs in computational quantum chemistry, however, hold promise for discovering catalysts that are “just right” and thousands of times faster than standard approaches. Associate Professor John Keith and his lab group are using new quantum chemistry computing procedures to categorize hypothetical electrocatalysts that are “too slow” or “too expensive,” far more thoroughly and quickly than was considered possible a few years ago. Keith is also the Richard King Mellon Faculty Fellow in Energy. The Keith Group’s research compilation, “Computational Quantum Chemical Explorations of Chemical/Material Space for Efficient Electrocatalysts,” was featured in Interface, a quarterly magazine of The Electrochemical Society. “For decades, catalyst development was the result of trial and error – yearslong development and testing in the lab, giving us a basic understanding of how catalytic processes work. Today, computational modeling provides us with new insight into these reactions at the molecular level,” Keith explained. “Most exciting however is computational quantum chemistry,
which can simulate the structures and dynamics of many atoms at a time. Coupled with the growing field of machine learning, we can more quickly and precisely predict and simulate catalytic models.” In the article, Keith explained a three-pronged approach for predicting novel electrocatalysts: 1) analyzing hypothetical reaction paths; 2) predicting ideal electrochemical environments; and 3) high-throughput screening powered by alchemical perturbation density functional theory and machine learning. The article explains how these approaches can transform how engineers and scientists develop electrocatalysts needed for society. “These emerging computational methods can allow researchers to be more than a thousand times as effective at discovering new systems
compared to standard protocols,” Keith said. “For centuries chemistry and materials science relied on traditional Edisonian models of laboratory exploration, which bring far more failures than successes and thus a lot of wasted time and resources. “Traditional computational quantum chemistry has accelerated these efforts, but the newest methods supercharge them. This helps researchers better pinpoint the undiscovered catalysts society desperately needs for a sustainable future.”
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Investigating a Thermal Challenge for MOFs
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o the naked eye, metal organic frameworks (MOFs) look a little like sand. But if you zoom in, you will see that each grain looks and acts more like a sponge – and serves a similar purpose.
MOFs are used to absorb and hold gases, which is useful when trying to filter toxic gases out of the air or as a way to store fuel for natural gas- or hydrogen gas-powered engines. New research led by an interdisciplinary team across six universities examines heat transfer in MOFs and the role it plays when MOFs are used for storing fuel. Corresponding author Christopher Wilmer, William Kepler Whiteford Faculty Fellow and assistant professor of chemical and petroleum engineering, coauthored the work with researchers at Carnegie Mellon University, the University of Virginia, Old Dominion University, Northwestern University, and the Karlsruhe Institute of Technology in Karlsruhe, Germany. The findings were published in Nature Communications. “One of the challenges with using MOFs for fuel tanks in cars is that you have to be able to fill up in a few minutes or less,” explained Wilmer. “Unfortunately, when you quickly fill these MOF-based tanks with hydrogen or natural gas, they get very hot. It’s not so much a risk of explosion – though there is one – but the fact that they can’t store much gas when they’re hot. The whole premise of using them to store a lot of gaseous fuel only works at room temperature. For other industrial applications you face a similar problem – whenever gases are loaded quickly the MOFs become hot and no longer work effectively.” In other words, for MOFs to be useful for these applications, they would need to be kept cool. This research looked at thermal transport in MOFs, to explore how quickly they can shed excess heat, and the group found some surprising results.
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“When you take these porous materials, which to begin with are thermally insulating, and you fill them with gas, it appears that they become even more insulating. This is surprising because usually, empty pockets like those in insulation or double-paned windows provide good thermal insulation,” explained Wilmer. “By taking porous materials and filling them, thereby removing those gaps, you would expect the thermal transport to improve, making it more thermally conductive. The opposite happens; they become more insulating.” To reach their conclusion, researchers conducted two simultaneous experiments using two different methods and MOFs synthesized in two different labs. Both groups observed the same trend: that the MOFs become more insulated when filled with adsorbates. Their experimental findings were also validated by atomistic simulations at Pitt in collaboration with Carnegie Mellon University. “Our work indicates potential challenges ahead for the use of MOFs outside of research labs, but that is a necessary step in the process,” said Alan McGaughey, professor of mechanical engineering at Carnegie Mellon. “As these materials advance toward broad, real-world usage, researchers will need to continue investigating once-overlooked properties of these materials, like thermal transport, and find the best way to use them to fit our needs.”
health
Let’s (Not) Stick Together
New Pitt Research Examines Mechanics of Mucus in Cystic Fibrosis Patients If you’ve ever had a cold, you know that too much mucus can be an annoyance, but mucus plays a very important role in the body. The respiratory system creates mucus as part of the immune system, meant to trap inhaled bacteria, viruses, and dirt so they can be removed before causing infection. However, for people with the genetic disorder cystic fibrosis (CF), the mucus that their bodies produce is thicker and stickier, leading to an increased risk from infection and decreased ability to breathe over time. New research led by Tagbo Niepa, assistant professor of chemical and petroleum engineering, examines the properties of the mucus of CF patients and the role it plays in a pathogens’ ability to survive. The new information could have important implications for CF treatment. The researchers examined non-mucoid and mucoid strains of P. aeruginosa, a common pathogen that infects the lungs. P. aeruginosa adapts to the host environment mutating from a non-mucoid phenotype (PANT) to a mucoid phenotype (PASL). This mutation in P. aeruginosa creates a protective film of mucus around the bacteria thereby forming a more hydrated and slimy biofilm in the mucus. “Think of the cells like grains of rice. PANT cells are like basmati rice, while PASL cells are like sushi rice: coated in such a way that they stick together when they’re compressed,” explained Niepa, who also holds appointments in the departments of Bioengineering, Civil and Environmental Engineering, and Mechanical
Engineering and Materials Science. “We can measure how investigational drugs can alter the sticky nature of the coating that pathogens such as P. aeruginosa create upon mutation.” This mutation gives the mucus unique properties that contribute to increased antibiotic resistance. It also shields them against phagocytic cells, which help the immune system clear out dead or harmful cells by ingesting them. In order to study these properties, the researchers used pendant drop elastometry to compress and expand the biofilm that the cells formed. They also assessed the transcriptional profile of the cells to correlate the film’s mechanics to cell physiology. “This is the first time that the pendant drop elastometry technique has been used to study the mechanics of these cells. We demonstrate that these techniques can be used to investigate the efficacy of mucolytic drugs – drugs that are used to break down the film of mucus that the cells are making,” noted Niepa. “This technique could be powerful for investigating those agents, to see if they have the anticipated effect.” The paper, “Material properties of interfacial films of mucoid and nonmucoid Pseudomonas aeruginosa isolates,” (DOI: 10.1016/j.actbio.2020.10.010) was published in the journal Acta Biomaterialia. It was authored by Sricharani Rao Balmuri, Nicholas G. Waters, and Tagbo H.R. Niepa from Pitt, and Jonas Hegemann and Jan Kierfeld from the Universität Dortmund in Dortmund, Germany. Spring 2021 | 5
Engineering a New Model for Respiratory Infection Treatment
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hen a person contracts a respiratory viral infection like COVID-19 or influenza, the immune system responds in a myriad of ways to eliminate the virus. Respiratory viral infections are so dangerous, however, because excessive immune responses may cause extreme lung inflammation. New modeling research may help doctors better predict and treat patients who are most at risk to that extreme response.
Jason Shoemaker, assistant professor of chemical and petroleum engineering, believes engineering-based mathematical modeling can help clinicians understand why some people’s immune systems react so severely, predicting the risk factors and pinpointing the most effective treatments to reduce inflammation. The National Science Foundation granted Shoemaker a CAREER Award for $547,494 over five years to create computational models of the immune response to seasonal, deadly (avian) influenza viruses, which can help identify the best way to suppress immune activity and reduce tissue inflammation. Since this work targets the immune system and not the specific virus, the models are expected to impact many respiratory infections, including COVID-19. “The immune system is a complex, interactive, dynamic system. Its goal is to clear the infection while minimizing collateral damage to the lungs and other organs in the process. But when it comes to respiratory infections, it’s been known that your immune response can do more damage than it should,” said Shoemaker. “Engineeringbased mathematical modeling approaches
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are ideal for simulating such a complex system and predicting the system’s response to viral infections and treatment.” Even outside of the current pandemic, respiratory virus infections are a constant threat to public health. Seasonal influenza can result in up to 700,000 hospitalizations and 56,000 deaths in the United States. Shoemaker’s models will enable researchers to uncover the biochemical markers that lead to excessive immune responses in respiratory infections and will help identify the best method for suppressing immune activity in those cases. In addition to this research, Shoemaker and his team will develop virtual reality (VR) games to teach the public about the immune system. “Our computational work is not tangible, and it’s hard to engage our community with something they can’t see or touch,” said Shoemaker. “The idea behind our VR games is to create a virtual environment to allow someone to dive in and observe the chemical behaviors of the immune system, seeing up close how they can lead to a dysregulation of the immune system and severe disease.”
Fueling the Future Like Oil and Water
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n the petroleum industry, the ability to separate oil and water is critical. Oily wastewater from drilling and processing crude oil is the biggest waste stream in the oil and gas industry, which produces three times as much waste as it does product.
Lei Li, associate professor of chemical and petroleum engineering, has received $110,000 from the American Chemical Society (ACS) Petroleum Research Fund (PRF) for his work developing 3D-printed membranes that will aid in oil-water separation. The development could help convert the oily wastewater into purified, usable water. “The ideal case for a membrane that serves this purpose is a material that is oleophobic and hydrophilic – in other words, one that hates oil but loves water,” said Li. “What’s new about this work is its focus on surface and in-pore topography: The texture of the surface of the material and even the texture inside of the pores of the material have a profound effect on the membrane’s effectiveness.” Current fluorinated hydrophilic and oleophobic membranes have been shown to be effective in the short-term but lose their properties in the long-term. Li’s method will instead rely on water as a thermodynamically stable material and will engineer the surface topography inside the membrane’s pores so that the water and oil remain separated. “Previously, such features were fabricated by nanolithography methods, which are slow and expensive. In this project, we propose to take advantage of two-photon polymerization 3D-printing technique,” explained Li. “Compared to traditional manufacturing technology, this provides a reasonably fast, single-step process to fabricate complicated structures.” Additionally, the high resolution that two-photon polymerization 3D-printing enables will allow the researchers to make the membrane’s pore size down to a few hundred nanometers, which is critical in separating oil-water emulsions.
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Uncovering the Nitty-Gritty Details of Surface Tension and Flow Behavior
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ry sand can be poured out of a bucket almost like a liquid; if you try to build a sandcastle with dry sand, you won’t have much luck. However, if you add just a little bit of water, everything about the sand’s behavior changes: It cannot be poured like a liquid and, instead, holds together well enough to build something. That difference is an example of how surface tension affects flow behavior, an element that is crucial in a variety of physical processes that involve mixing together liquid and solid particles. Sachin Velankar, professor of chemical and petroleum engineering, received $291,968 from the National Science Foundation for his collaborative research that seeks to better understand these phenomena. Velankar holds a secondary appointment in the Department of Mechanical Engineering and Materials Science. “Dry sand is really a mix of sand particles and air. The reason wet sand behaves so differently from dry sand is that water wants to wet the sand particles more than air does,” explained Velankar. “If you take the wet sand and look under a microscope, you’ll see that between each pair of sand particles is a ring of water – a meniscus – sticking them together. That’s why the wet sand can’t be poured: the granules just won’t separate easily. We want to understand how such wet particles separate under flow.”
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Velankar will partner with Charles Schroeder, professor of chemical and biomolecular engineering at the University of Illinois - UrbanaChampaign, on the project. The two will not be looking at sand, however. Instead, they will use state-of-the-art technology to manipulate microscopic particles suspended in fluid to study their behavior, the conditions that bind them together and the force necessary to break them apart. “I’ve been working in this area for more than 10 years and thought about questions of micromechanics for a long time but didn’t know how to approach it,” said Velankar. “It’s hard to manipulate particles precisely at this scale. That’s where the collaboration comes in.” Schroeder’s method involves a small microfluidic device, called a Stokes trap, with strategically placed channels for incoming and outgoing liquid streams. The particles, suspended in the chamber, are manipulated as liquid flows through the different channels.
The research will provide a fundamental understanding of the dynamics and rupture of particle clusters in well-defined flows. Understanding the micromechanics of this phenomenon will inform the way materials are mixed and separated in many industries that rely on the mixing of solids and liquids, from oil drilling to 3D printing to the food industry. The project, titled “Collaborative Research: Micromechanics of Meniscus-bound Particle Clusters,” received a total of $510,000 with $291,968 assigned to Pitt.
Modeling the World’s Refineries
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etroleum refining is the third-largest global source of stationary greenhouse gas (GHG) emissions and accounts for about 40 percent of emissions from the gas and oil supply chain, according to the IEA’s World Energy Outlook. The refining industry has had to adjust to keep up with changing market demands and increasing environmental regulations. However, not every type of crude oil has an equal impact, and those who use and sell petroleum products are not aware of the environmental footprint each refining process has. New research in the journal Nature Climate Change uses engineering-based refinery modeling on crude oils to assess and track the lifecycle climate impacts of the oil and gas industry. The authors, including Mohammad Masnadi, assistant professor of chemical and petroleum engineering, provide guidance on refining choices that will lessen the environmental impact of the industry and recommend future investments in emissions mitigation technologies. “This paper helps to define a detailed baseline of current global refining emissions at a crude and country level, as well as an investigation of the drivers of these emissions and mitigation potential
using a transparent, open-source tool. This provides a scientific basis for transparently tracking emissions reduction progress from this sector,” said Masnadi. “Our work can help policy makers quantitatively to design better energy and environmental strategies and provide insights for investors and risk assessors in their future decision making process in a carbon-constrained world.” The researchers modeled 93 percent of the world’s oil as it flows to 153 refineries, finding that global refining emissions could potentially be reduced by 11 to 58 percent by targeting the primary emission sources. The research will, for the first time, estimate GHG emissions of oil refinery operations using a granular, engineering-based, bottom-up approach. The paper, “Carbon intensity of global crude oil refining and mitigation potential,” (DOI: 10.1038/s41558-020-0775-3) was led by the University of Calgary’s Liang Jing and co-authored by the Aramco Research Center’s Hassan M. El-Houjeiri and Jean-Christophe Monfort; Stanford University’s Adam R. Brandt; Pitt’s Mohammad S. Masnadi; Brown University’s Deborah Gordan; and the University of Calgary’s Joule A. Bergerson.
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Mimicking Cancer to Avoid Transplant Rejection
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nspired by a tactic used by cancer cells to evade the immune system, Pitt researchers have engineered tiny particles that can trick the body into accepting transplanted tissue as its own.
packaging it all up in an engineered system that recruits these naturally occurring cells right to the transplanted graft,” said lead author James Fisher, MD, PhD, a postdoctoral researcher in the Pitt School of Medicine.
Rats that were treated with these cell-sized microparticles developed permanent immune tolerance to grafts – including a whole limb – from a donor rat, while keeping the rest of their immune system intact, according to a paper published in Science Advances.
The microparticles work by releasing a native protein secreted by tumors, CCL22, which draws regulatory T cells (Treg cells) to the site of the graft, where they tag the foreign tissue as “self” so that it evades immune attack.
“It’s like hacking into the immune system borrowing a strategy used by one of humanity’s worst enemies to trick the body into accepting a transplant,” said senior author Steven Little, PhD, William Kepler Whiteford Endowed Professor and Chair of chemical and petroleum engineering. “And we do it synthetically.”
Microparticle-treated animals maintained healthy grafts for as long as they were monitored – a little under a year, equivalent to about 30 human years. All it took was two shots to affect seemingly permanent change.
The advantage of a synthetic approach rather than cell-based therapy, which is currently in clinical trials, is that the treatment logistics are much simpler.
In a companion paper published in PNAS, the researchers showed that these engineered microparticles can train the immune system of one strain of rat to accept a donor limb from a different strain. This new paper shows that the effects are specific to the intended donor. Skin grafts from a third strain were rapidly rejected.
“Instead of isolating cells from a patient, growing them up in the lab, injecting them back in and hoping they find the right location, we’re
Today, transplant patients take daily doses of immunosuppressant drugs to avoid rejection, leaving them vulnerable to cancer, diabetes,
infectious diseases and a host of other ailments that come along with a weakened immune system. “These drugs hammer the immune system into submission so it can’t attack the transplanted organ, but then it can’t protect the body either,” said coauthor Stephen Balmert, PhD, a postdoctoral researcher in the Pitt School of Medicine. “We’re trying to teach the immune system to tolerate the limb, so that a transplant recipient can remain immunocompetent.” The risks of lifelong immunosuppression are particularly problematic when the transplant isn’t a life-saving procedure. Doctors and patients have to consider whether the benefits outweigh the risks. “The ability to induce transplant tolerance while avoiding systemic immunosuppression, as demonstrated in these innovative studies, is especially important in the context of vascularized composite transplantation where patients receive quality-of-life transplants, such as those of hands or face,” said coauthor Angus Thomson, PhD, professor of surgery and immunology in the Thomas E. Starzl Transplantation Institute at Pitt. Written by Erin Hare, UPMC
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Breathing Easier with a Better Tracheal Stent Pitt Researchers Demonstrate First Successful Use of Biodegradable Magnesium-Alloy Stent for Pediatric Patients
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ediatric laryngotracheal stenosis (LTS), a narrowing of the airway in children, is a complex medical condition. While it can be something a child is born with or caused by injury, the condition can result in a life-threatening emergency if untreated. Treatment, however, is challenging. Depending on the severity, doctors will use a combination of endoscopic techniques, surgical repair, tracheostomy, or deployment of stents to hold the airway open and enable breathing. While stents are great at holding the airway open and simultaneously allowing the trachea to continue growing, they can move around, or cause damage when they’re eventually removed. New research led by the University of Pittsburgh is poised to drastically improve the use of stents, demonstrating for the first time the successful use of a completely biodegradable magnesium-alloy tracheal stent that avoids some of these risks. “Using commercial non-biodegradable metal or silicone based tracheal stents has a risk of severe complications and doesn’t achieve optimal clinical outcomes, even in adults,” said Prashant N. Kumta, Edward R. Weidlein Chair Professor of Bioengineering. “Using advanced biomaterials could offer a less invasive, and more successful treatment option.” In the study, the balloon-expandable ultra-high ductility (UHD) biodegradable magnesium stent was shown to perform better than current metallic nonbiodegradable stents in use in both in lab testing and in rabbit models.
The stent was shown to keep the airway open over time and have low degradation rates displaying normal healing no adverse problems. “Our results are very promising for the use of this novel biodegradable, high ductility metal stent, particularly for pediatric patients,” said Kumta, who also holds appointments in Chemical and Petroleum Engineering, Mechanical Engineering and Materials Science, and the McGowan Institute for Regenerative Medicine. “We hope this new approach leads to new and improved treatments for patients with this complex condition as well as other tracheal obstruction conditions including tracheal cancer.” The paper, “In-vivo efficacy of biodegradable ultrahigh ductility Mg-Li-Zn alloy tracheal stents for pediatric airway obstruction,” (DOI: 10.1038/s42003020-01400-7), was authored by the Swanson School’s Jingyao Wu, Abhijit Roy, Bouen Lee, Youngjae Chun, William R. Wagner, and Prashant N. Kumta; UPMC’s Leila Mady, Ali Mübin Aral, Toma Catalin, Humberto E. Trejo Bittar, and David Chi; and Feng Zheng and Ke Yang from The Institute of Metal Research at the Chinese Academy of Sciences.
New research led by the University of Pittsburgh is poised to drastically improve the use of tracheal stents for children with airway obstruction. Researchers demonstrate for the first time the successful use of a completely biodegradable magnesium-alloy tracheal stent, pictured, that safely degrades and does not require removal. (Credit: Materialise) Spring 2021 | 11
MODELING NANOCHEMISTRY Working on the Frontier of Nanoparticle Research
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field that is investigating something very small is becoming very big: In the last decade, nanoparticle research has exploded. At about one nanometer in size, nanoparticles are 100,000 times smaller than the width of a strand of human hair and cannot be seen with the naked eye, but researchers are discovering broad uses for them in fields ranging from bioimaging to energy and the environment. Working at this scale, it is difficult to be precise; however, the Computer-Aided Nano and Energy Lab (CANELa) is advancing the field, modeling metal nanoclusters that are atomically precise in structure. An article highlighting their work and its influence on the field of nanoparticles is featured on the cover of the latest issue of Dalton Transactions. “One major benefit of these very small systems is that by knowing their exact structure, we can apply very accurate 12 | Spring 2021
theory,” said Giannis “Yanni” Mpourmpakis, Bicentennial Alumni Faculty Fellow and associate professor of chemical engineering, who leads the CANELa. “With theory we can then investigate how properties of nanoclusters depend on their structure.” Ligand-protected metal nanoclusters are a unique class of nanomaterials that are sometimes referred to as “magic size” nanoclusters because of their high stability when they have specific compositions. One of the key advances their lab has made to the field, with funding from the National Science Foundation, is in modeling the specific number of gold atoms stabilized by a specific number of ligands, on the surface. “With larger nanoparticles, researchers may have an estimate of how many atoms exist on each structure, but our modelling of these nanoclusters is exact. We can write out the precise molecular formula,” explained Michael Cowan, graduate student in the CANELa and lead author on the article.
“If you know the exact structure of small systems you can tailor them to create active sites for catalysis, which is what our lab focuses on most.” Predicting new alloys and previously undiscovered magic sizes is the next step that the field – and the lab – will need to tackle. The lab uses computational chemistry methods to model known nanoclusters, but creating a complete database of nanocluster structure, property and synthesis parameters will be the next step to apply machine learning and create a prediction framework.
Let’s Do the Twist
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he twisting and bending capabilities of the human muscle system enable a varied and dynamic range of motion, from walking and running to reaching and grasping. Replicating something as seemingly simple as waving a hand in a robot, however, requires a complex series of motors, pumps, actuators and algorithms. Researchers at the University of Pittsburgh and Harvard University have recently designed a polymer known as a liquid crystal elastomer (LCE) that can be “programmed” to both twist and bend in the presence of light.
Modeling a Model Nanoparticle
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etal nanoparticles have a wide range of applications, from medicine to catalysis, from energy to the environment. But the fundamentals of adsorption – the process allowing molecules to bind as a layer to a solid surface – in relation to the nanoparticle’s characteristics were yet to be discovered. New research from the Swanson School of Engineering introduces the first universal adsorption model that accounts for detailed nanoparticle structural characteristics, metal composition and different adsorbates, making it possible to not only predict adsorption behavior on any metal nanoparticles but screen their stability, as well. The research combines computational chemistry modeling with machine learning to fit a large number of data and accurately predict adsorption trends on nanoparticles that have not previously been seen. By connecting adsorption with the stability of nanoparticles, nanoparticles can now be optimized in terms of their synthetic accessibility and application property behavior. This improvement will significantly accelerate nanomaterials design and avoid trial and error experimentation in the lab. “This model has the potential to impact diverse areas of nanotechnology with applications in catalysis, sensors, separations and even drug delivery,” says Giannis (Yanni) Mpourmpakis, the Swanson School’s Bicentennial Alumni Faculty Fellow and associate professor of chemical and petroleum engineering, whose CANELa lab conducted the research. “Our lab, as well as other groups, have performed prior computational studies that describe adsorption on metals, but this is the first universal model that accounts for nanoparticle size, shape, metal composition and type of adsorbate. It’s also the first model that directly connects an application property, such as adsorption and catalysis, with the stability of the nanoparticles.”
The research, published in the journal Science Advances was developed at the Swanson School by Anna C. Balazs, Distinguished Professor of Chemical and Petroleum Engineering and John A. Swanson Chair of Engineering; and James T. Waters, postdoctoral associate and the paper’s first author. These particular LCEs are achiral: the structure and its mirror image are identical. This is not true for a chiral object, such as a human hand, which is not superimposable with a mirror image of itself. In other words, the right hand cannot be spontaneously converted to a left hand. When the achiral LCE is exposed to light, however, it can controllably and reversibly twist to the right or twist to left, forming both right-handed and lefthanded structures. “The chirality of molecules and materials systems often dictates their properties,” Balazs explained. “The ability to dynamically and reversibly alter
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Faculty Feature
Leading by Example
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aryn Bayles, vice chair for undergraduate education and professor of chemical and petroleum engineering, has dedicated her career to sharing the joy of engineering with others. In recognition of her myriad contributions to the field of engineering education, she was honored with the ASEE 2020 Lifetime Achievement Award during the organization’s virtual conference on June 23, 2020. The award is presented to a Pre-College Engineering Education Division member who has “provided a high standard of service in alignment with the Division Vision, Mission and Core Beliefs and in support of pre-college engineering education efforts within the American Society of Engineering Education), and who has made significant and sustained contributions to the field of pre-college engineering.” Bayles’ research primarily focuses on engineering pedagogy, with the aim of making science and engineering more engaging and accessible for students from kindergarten through college. She has taught 7,200 instructors through more than 150 workshops how to introduce students to engineering principles. As part of her chemical engineering classes, her undergraduates share their knowledge with the local community through hands-on outreach activities. These efforts of Bayles’ 1000+ engineering students have benefitted more than 10,000 participating K-12 students. Bayles knows that early encounters can be an important first step toward a career in engineering. Her own first encounter with engineering was in high school when she received a scholarship to work at Sandia National Labs in Albuquerque, N.M. This experience and several more internships during college cemented her interest in chemical engineering. But her industry job after graduation revealed a passion for teaching. 14 | Spring 2021
“When I worked in industry, I led activities for young students during Engineers’ Week and through Junior Achievement, and it became addictive,” she said. “Every time I’ve gotten to teach, it has been so rewarding.” For more than two decades, Bayles has taught chemical engineering at institutions including Pitt, the University of Nevada Reno, the University of Maryland College Park and the University of Maryland Baltimore County. In the classroom, she regularly draws on her own industrial engineering experience, which has included process engineering, computer modeling and control, process design and testing, and engineering management at Exxon, Westinghouse and Phillips Petroleum. In between her career in industry and her career in academia, Bayles formatively stayed at home with her two children. When her daughter came home from school in the second grade with a note about cuts to the science curriculum, she wanted to make sure the students wouldn’t miss out on opportunities to learn about science and engineering. She started an afterschool program with hands-on STEM activities; even when her daughter was no longer in elementary school, she continued the program while her son was still in elementary school – and her daughter would help to co-lead the activities. “Those experiences made me realize how few resources there are for getting kids into engineering,” she said. “It drove me to create opportunities to encourage STEM learning. It sparked a passion and desire, and from there I set a course.”
In addition to teaching students directly about STEM, Bayles’ research and workshops have also taught teachers ways to make STEM accessible to their students. She has led middle school and high school teacher professional development for Project Lead the Way, and co-authored the INSPIRES (INcreasing Student Participation, Interest and Recruitment in Engineering & Science) curriculum, which introduces high school students to engineering design through hands-on experiences and inquiry-based learning with real world engineering design challenges. In her courses she incorporates her industrial experience by bringing practical examples and active learning to help students grasp fundamental engineering principles. Last year, Bayles was awarded the Department’s James Pommersheim Award for Excellence in Teaching Chemical Engineering, and she has served as the Chair of the American Institute of Chemical Engineers Education Division. In addition to her impressive teaching record and education research, Bayles has been a supportive advisor for Pitt’s AIChE Chem-E-Car team, which has excelled in recent years. “Taryn Bayles is quite simply a juggernaut in Engineering Education. She is a national leader and pioneer that is admired by the most distinguished engineering educators in our field,” said Steven Little, William Kepler Whiteford Endowed Professor and Chair of the Department of Chemical and Petroleum Engineering. “She is highly deserving of this award and the Department could not be more proud of her.”
Student Feature
“ I want to pursue a degree like this when I go to college”
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he Outreach Projects for ChE 500 “Systems Engineering I: Dynamics and Modelling,” a Pillars Curriculum course for senior students in Chemical and Petroleum Engineering, is an integral part of the course. The same groups that work out homework assignments, other projects, recitations or lab experiments are challenged with making a proposal for a community service where they address nontechnical audiences and promote the interest in or appreciation for STEM careers. The project, meant to help the engineering students engage with their field in a new way, had a significant impact on their audiences. Eleven groups of Pitt students reached a total of 12 teachers and 443 students ranging from thirdgraders to college students. Students were entirely free to choose their topics, their partners, their audiences, their communication tools, their service and their goals. The basic structure for the project required a proposal presentation early in the term, the approval of the instructor before the actual presentation to the selected audience, and a final presentation to the class, complemented by a group report and individual self-assessment reports. The final grades factored in self-assessment, community feedback and instructor grading. “Learning to communicate well about science is an important part of being an engineer,” says Joaquin Rodriquez, assistant professor of Chemical and Petroleum Engineering and ChE 500 instructor. “An important part of this project is practicing communication skills that will serve them for their academic and professional careers.” Many of the groups focused on breaking down engineering concepts for non-engineering audiences in a way that was engaging and hands-on. For some, that meant providing teachers with materials they can use in the classroom to bring STEM concepts to life. One group prepared a presentation for fourth and fifth grade students at Howe Elementary School and Holiday
Park Elementary School on how water is processed from natural sources and distributed to peoples’ homes. Another prepared a video and presentation about a chemical experiment, making a lava lamp, to third graders at Stewartsville Elementary School, and yet another prepared a lecture on forces, combined with a dynamic set of experiments to illustrate the different types of forces. Several other groups created websites with chemical engineering principles and fundamental information that teachers can use as a resource when presenting these concepts in the classroom. Other groups created in-person demonstrations designed to engage young audiences. One group prepared a background presentation and a set of three chemical reaction experiments – elephant tooth-paste, a vitamin C clock, and a Luminol demonstration – on stage at Freedom Area Middle School with about 100 sixth-graders in attendance. The students were invited to take part in the experiments, a call they answered with enthusiasm. continued on page 18
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PhDs Conferred Spring 2020 Yasemin Basdogan (Advisor: Dr. John A. Keith) Understanding Solvation Environments in Chemical Systems
’ g n i ‘Zoom
to the Finish Line
Pitt Students Qualify for Virtual International Chem-E-Car Competition The Pitt Chem-E-Car team competed virtually at the AIChE Annual Student Conference’s International Chem-E-Car Competition on November 15. After noticing the fuel cell was malfunctioning in October’s regional competition, the team had to redesign the car around a different propulsion mechanism – a lead acid battery – just 24 hours before the competition. With their new design approved, the team completed their runs, bringing home the Sportsman Award for their perseverance and the First Place Chem-E-Car Video Award. “I am incredibly proud of the team – they faced so many challenges and obstacles this year, with limited time to work on the car due to COVID-19,” remarked the team’s advisor Taryn Bayles, vice chair of undergraduate education and professor of chemical and petroleum engineering at Pitt. “I am most impressed with their determination to completely redesign their car less than 24 hours before the competition.”
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Pavithra Murugavel Shanthi (Advisor: Dr. Prashant N. Kumta) Fundamental Study of Engineered Cathode and Li-ion Conducting Electrolyte Architectures for High Energy Density Lithium Sulfur Batteries Kutay Berk Sezginel (Advisor: Dr. Christopher E. Wilmer) Computational Materials Design for Molecular Machinery: From Nanoporous Crystals to Nanoscale Racecars Minh Ngueyn Vo (Advisor: Dr. J. Karl Johnson) Quantum Chemical Studies of Reaction Pathways and Thermophysical Properties of Materials Muying Wang (Advisor: Dr. Jason E. Shoemaker) Big Data Approaches to Improving the Identification of Drug or Disease Mechanisms for Drug Innovation Junyu Yang (Advisor: Dr. Sachin S. Velankar) Irreversible Effects in Thin Film Buckling and Development of a High Temperature Thermoplastic Foam
Fall 2019 Alexandra G. May (Advisor: Dr. William J. Federspiel) Development of the Modular Extracorporeal Lung Assist System (ModELAS): ECCO2R and Pediatric Applications Gianfranco Rodriguez (Advisor: Dr. Eric Beckman) Modelling of Multiphasic Behavior of Biodiesel Transesterification Operating Below Critical Conditions Using CO2 as a Co-solvent with PC-SAFT EoS Siying Zhang (Advisor: Dr. Joseph J. McCarthy) Modeling of the Flow Dynamics through Incompressible Porous Media in SolidLiquid Filtration
Summer 2019 Derrick Amoabeng (Advisor: Dr. Sachin S. Velankar) Fundamentals and Material Science Aspects of Particle Filled Polymer Blends Alec Reino Kaija (Advisor: Dr. Christopher E. Wilmer) Porous Pseudomaterials for Studying Structure-Property Relationships of Gas Adsorption Florencio Serrano Castillo (Advisors: Dr. Robert S. Parker and Dr. Timothy E. Corcoran) Multi-Scale Mathematical Models of Airway Epithelium to Facilitate Cystic Fibrosis Treatment Michael G. Taylor (Advisor: Dr. Giannis Mpourmpakis) Ligand-Protected Nanocluster Stability, Doping, and Prediction Yahui Yang (Advisor: Dr. Götz Veser) Towards a More Sustainable Chemical Process Industry: Engineering Nanocatalysts for Natural Gas Utilization and Carbon Dioxide Conversion
Let’s Do the Twist... continued from page 13 chirality or drive an achiral structure into a chiral one could provide a unique approach for changing the properties of a given system on-the-fly. To date, however, achieving this level of structural mutability remains a daunting challenge. Hence, these findings are exciting because these LCEs are inherently achiral but can become chiral in the presence of ultraviolet light and revert to achiral when the light is removed.” The researchers uncovered this distinctive dynamic behavior through their computer modeling of a microscopic LCE post anchored to a surface in air. Molecules (the mesogens) that extend from the LCE backbone are all aligned at 45 degrees (with respect to the surface) by a magnetic field; in addition, the LCEs are crosslinked with a light-sensitive material. “When we simulated shining a light in one direction, the LCE molecules would become disorganized and the entire LCE post twists to the left; shine it in the opposite direction and it twists to the right,” Waters described. These modeling results were corroborated by the experimental findings from the Harvard group. Going a step further, the researchers used their validated computer model to design “chimera” LCE posts where the molecules in the top half of the post are aligned in one direction and are aligned in another direction in the bottom half. With the application of light, these chimera structures can simultaneously bend and twist,
mimicking the complex motion enabled by the human muscular system. “This is much like how a puppeteer controls a marionette, but in this instance the light serves as the strings, and we can create dynamic and reversible movements through coupling chemical, optical, and mechanical energy,” Balazs said. “Being able to understand how to design artificial systems with this complex integration is fundamental to creating adaptive materials that can respond to changes in the environment. Especially in the field of soft robotics, this is essential for building devices that exhibit controllable, dynamic behavior without the need for complex electronic components.”
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I want to pursue a degree like this... continued from page 15
The projects weren’t all geared toward a K-12 audience, though; others sought to reach nonengineering majors to show how engineering impacts everyone. One group prepared a video about the Haber-Bosch process and its dramatic impact on agriculture to sustain a growing world population. The video was presented at a meeting of the Pitt Muslim Students Association, a group with a diverse educational background. Another prepared a video with animations on the scientific principles behind the operation of microwave ovens to a class of non-STEM major students at Pitt. “Our students each found unique ways to engage with their audiences and make science exciting, enjoyable, and importantly, clear,” said Rodriguez. “They were strong ambassadors for the field of chemical engineering and STEM careers, and I’m proud of the impact our students have in our community.” The feedback provided by the students and teachers shows the great impact these outreach efforts had. In response to a group’s website detailing solar power and chemical engineers’ role in it, the instructor said, “The site provided a lot of useful information on how prevalent these forms of sustainable energy are becoming in the United States and around the world, which started several side conversations with my students about the importance of sustainable energy – which, I believe, is alone the marking of a huge success. To have tapped into the interests of teenagers to such a degree that they talk about renewable energy with interest is, truly, a remarkable feat.”
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AWARDS HONORS 2020 Faculty Promotions and Appointments Dr. Chris Wilmer Associate Professor with tenure Dr. Susan Fullerton Associate Professor with tenure Dr. Sachin Velankar, Professor
Faculty Awards In recognition of her remarkable mentorship and teaching, Taryn Bales, vice chair for education and professor of chemical engineering, has been awarded the James Pommersheim Award for Excellence in Teaching Chemical Engineering. The Pommersheim Award was established by the Department and James M. Pommersheim ‘70 to recognize departmental faculty in the areas of lecturing, teaching, research methodology, and research mentorship of students. Pommersheim, formerly Professor of Chemical Engineering at Bucknell University, received his bachelor’s, master’s and PhD in chemical engineering from Pitt. The world’s leading organization for delivery science and technology has recognized Professor Steven R. Little with election to its College of Fellows. The Controlled Release Society elevated Little, the William Kepler Whiteford Endowed Professor and Chair of Chemical and Petroleum Engineering, for outstanding and sustained contributions to the field of delivery science and technology over a minimum of ten years. From the design of improved batteries to the use of solar and wind power for commodity chemical
production, Assistant Professor James McKone explores ways that chemical engineering can make the world more sustainable. That’s why his most recent work, investigating ways that the chemical industry can use renewable electricity as its energy source, is featured in the Journal of Materials Chemistry A Emerging Investigators special issue. The themed issue highlights the rising stars of materials chemistry research, from nanoparticle inks to next-generation solar cells. The featured investigators are early in their careers and were recommended by other experts in the field. Susan Fullerton, Bicentennial Board of Visitors Faculty Fellow and assistant professor of chemical engineering, has been selected as a 2020 Alfred P. Sloan Research Fellow in Chemistry. The highly competitive award is given to outstanding early-career scientists from the U.S. and Canada. The two-year, $75,000 fellowship recognizes researchers’ unique potential to make substantial contributions to their field. Fullerton’s fellowship will further her research on two-dimensional materials for next-generation electronics. These two-dimensional materials can be thought of as a piece of paper – if the paper were only a single molecule thick. Fullerton’s group uses ions to control charge in these molecularly thin sheets for application in memory and logic. Fullerton is the 12th Pitt faculty member to receive the Chemistry Fellowship since 1970. In recognition of his contributions to the field of petroleum engineering, Badie Morsi, professor and director of the Petroleum Engineering Program, was awarded the Society of Petroleum
Engineers’ (SPE) Regional Distinguished Achievement Award for Petroleum Engineering Faculty. The Award is given to a SPE member in recognition of their excellence in classroom teaching, research, advising and guiding students, and contributions to the field of petroleum engineering. Morsi is the long-standing director of Pitt’s petroleum engineering program, which offers undergraduate electives, a minor, a concentration, and an MS degree.
Student Awards Luke Rattay and Ryan Mowry received Lewis E. and Elizabeth W. Young Scholarships from the Women’s Auxiliary American Institute of Mining, Metallurgical and Petroleum Engineers, Inc. – PENNSYLVANIA – WESTERN SECTION. Samantha Bunke, an undergraduate researcher in the Fullerton Lab, received the 2019 Co-op Trailblazer Award. The award is in recognition of her outstanding cooperative education work at EQT. Jonathan Klan received the 2019 Pittsburgh Quantum Institute (PQI) Award, which is given in recognition of an outstanding undergraduate poster presentation at Pitt’s Science2019 event.
Honoring the Next Generation in Engineering Research
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or the second consecutive year, a graduate student from the Swanson School of Engineering has won the AIChE’s Computational Molecular Science and Engineering Forum (CoMSEF) annual Graduate Student Award. Yasemin Basdogan, a doctoral student in chemical engineering, was awarded the honor in recognition of her significant contributions in her work on using machine learning to study local solvation environments with John Keith, associate professor of chemical engineering and R.K. Mellon Faculty Fellow in Energy. “Yasemin is a tremendous student, and I was happy to nominate her for this national award,” said Keith. “Awards like this showcase the impressive work of our students and are a great way for them to get visibility and be well-prepared for an ultra-competitive academic job market. They also demonstrate our department’s success in personalizing the training and mentoring of our great students to achieve their goals.” The work uses computational tools to study ion solvation environments, an approach that will be useful for the atomistic modeling of ions in different solvents. Last year, Michael Taylor, working with Giannis (Yanni) Mpourmpakis, was awarded the honor for his work on computer-aided descriptions of materials stability at the nanoscale. The prize comes with a plaque and an honorarium. Students are nominated by their dissertation advisor and must present a poster at the CoMSEF Poster Session at the AIChE Annual Meeting. Awards are based on the student’s CV, the nomination letter from their advisor, the quality of the poster and the student’s ability to describe their research. “As researchers, pursuing impactful research is our primary goal, but being able to effectively communicate that research is a challenging but vital skill to learn,” said Keith. “This recognition shows that Yasemin is poised to continue excelling at both.”
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Swanson School of Engineering Department of Chemical and Petroleum Engineering 940 Benedum Hall 3700 O’Hara Street Pittsburgh PA 15261
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Engineering a (Sanitizing) Solution
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hen labs at the Swanson School of Engineering closed for research purposes, Götz Veser, the Nickolas DeCecco Professor of Chemical and Petroleum Engineering and associate director of the Center for Energy, looked for a way his equipment could be put to use during the COVID-19 pandemic. Riddhesh Patel, one of Veser’s graduate students, had an idea: Use the lab’s large-scale batch reactors – essentially enormous stirred glass containers – to blend hand sanitizer for UPMC, which is experiencing a severe shortage for their medical personnel. After receiving permission to return to the Pittsburgh campus, Veser, Patel and graduate student Nasser Al Azri set to work. Al Azri maintains and cleans the equipment with support from Patel, as the scope of the effort has increased. Veser supervises production, solicits donations of chemicals needed and shuttles the sanitizer to UPMC’s South Side operation. “I do what any good professor does: Stay out of the way and make sure that my students have what they need to do their good work,” he said. To date, the lab has produced more than 150 gallons of sanitizer and plans to continue to produce sanitizer as long as it can get supplies.
UNIVERS ITY OF PI T T SBURGH | SWANSON SC H O O L O F EN G I N EER I N G | E N G I N E E R I N G . P I T T. E D U / C H E M I C A L