A new kind of polymer membrane created by researchers at Georgia Tech could reshape how refineries process crude oil, dramatically reducing the energy and water required while extracting even more useful materials.

The so-called DUCKY polymers — more on the unusual name in a minute — are reported Oct. 16 in Nature Materials. And they’re just the beginning for the team of Georgia Tech chemists, chemical engineers, and materials scientists. They also have created artificial intelligence tools to predict the performance of these kinds of polymer membranes, which could accelerate development of new ones.

The implications are stark: the initial separation of crude oil components is responsible for roughly 1% of energy used across the globe. What’s more, the membrane separation technology the researchers are developing could have several uses, from biofuels and biodegradable plastics to pulp and paper products.

“We're establishing concepts here that we can then use with different molecules or polymers, but we apply them to crude oil because that's the most challenging target right now,” said M.G. Finn, professor and James A. Carlos Family Chair in the School of Chemistry and Biochemistry.

Read the full story on the College of Engineering website.

Research faculty at the Georgia Institute of Technology now have their own advocacy group. Since 2022, the Research Faculty Advisory Council (RFAC) has increased research faculty engagement and addressed concerns from researchers in the Interdisciplinary Research Institutes (IRIs), joining similar organizations that address such needs in other colleges.

The group addresses issues such as retention, professional development, recognition, and compensation. Julia Kubanek, vice president for Interdisciplinary Research (VPIR), formed the group after hearing feedback from research faculty and modeled it after a similar council in the College of Sciences.

“This advisory council has helped clarify how we can improve both the status and experience of research faculty on campus,” Kubanek said. “The recommendations they’ve provided and the initiatives they’ve launched are already making a difference.”

The 12 members are nominated from across the IRIs, plus two other interdisciplinary research units supported by the VPIR. These members include:

 

• Vishwadeep Ahluwalia (Center for Advanced Brain Imaging)
• Michael Chang (Brook Byers Institute for Sustainable Systems)
• Sriram Chockalingam (Institite for Data Engineering and Science)
• Christine Conwell (Strategic Energy Institute)
• Andrew Dugenske (Georgia Tech Manufacturing Institute)
• Ulrika Egertsdotter (Renewable Bioproducts Institute)
• Evan Goldberg (Global Center for Medical Innovation )
• Walter Henderson (Institute for Materials)
• Johannes Leisen (Parker H. Petit Institute for Bioengineering and Bioscience)
• Paul Joseph (Institute for Electronics and Nanotechnology)
• Leanne West (Pediatric Technology Center)
• Clint Zeagler (Institute for People and Technology)

In its first year, RFAC had two co-leads: Andrew Dugenske, the director of the Factory Information Systems Center and a principal research engineer at the Georgia Tech Manufacturing Institute, and Paul Joseph, a principal research scientist and director of External User Programs for Southeastern Nanotechnology Infrastructure Corridor.

“Although the research faculty contribute significantly to the overall growth of Georgia Tech, we remain largely underrepresented, unrecognized, and underemployed because of the lack of suitable platforms to talk about the challenges faced by research faculty colleagues,” Joseph said. “It was not a surprise that the same concerns surfaced and were discovered by the council when we collected input from the research faculty throughout the IRIs on issues that concern and are important to research faculty.”

Although Joseph and Dugenske have completed their terms in their leadership roles, they are satisfied with RFAC’s initial success in creating awareness of research faculty challenges on campus, and initiatives that include a mentorship program with the Research Next team, a Research Faculty Mentoring Network, and efforts in RFAC bylaws creation. Leanne West and Walter Henderson now serve as co-leads.

“It was great for the administration to recognize the many contributions that research faculty make to the Institute and establish a way to improve research faculty job satisfaction and engagement,” Dugenske said. “During the first year of the RFAC, the committee did a great job of gathering issues of importance to research faculty and presenting clear and actionable recommendations to decision-makers.”

Nga Lee (Sally) Ng, Love Family Professor with joint appointments in the School of Chemical and Biomolecular Engineering and School of Earth and Atmospheric Sciences, is AGU's 2023 Atmospheric Sciences Ascent Award recipient.

The Atmospheric Sciences Ascent Award is presented annually and recognizes excellence in research and leadership in the atmospheric and climate sciences from honorees between eight and 20 years of receiving their PhD.

Being selected as a Section Honoree is bestowed upon individuals for meritorious work or service toward the advancement and promotion of discovery and solution science. AGU, the world's largest Earth and space science association, annually recognizes a select number of individuals as part of its Honors and Recognition program.

The Atmospheric Sciences Section studies the physics, chemistry, and dynamics of the atmosphere. Ng received the Ascent Award for advancing the fundamental understanding of organic aerosol measurement, sources, chemistry, trends, and impacts in Earth’s atmosphere.

Ng earned her doctorate in Chemical Engineering from the California Institute of Technology and was a postdoctoral scientist at Aerodyne Research Inc. She joined Georgia Tech as an assistant professor in 2011.

Her research focuses on the understanding of the chemical mechanisms of aerosol formation and composition, as well as their health effects. Her group combines laboratory chamber studies and ambient field measurements to study aerosols using advanced mass spectrometry techniques.

Ng currently leads the establishment of the Atmospheric Science and Chemistry mEasurement NeTwork (ASCENT), a new comprehensive, high-time-resolution, long-term measurement network in the U.S. for the characterization of aerosol chemical composition and physical properties. Ng is the inaugural editor-in-chief of the American Chemical Society's (ACS)  ACS ES&T Air, a new journal that will publish novel and globally relevant original research on all aspects of air quality sciences and engineering.

Honorees will be recognized at AGU23, which will convene more than 25,000 attendees from over 100 countries in San Francisco and online everywhere on 11-15 December 2023. This celebration is a chance for AGU’s community to recognize the outstanding work of our colleagues and be inspired by their accomplishments and stories.

Gigatons of greenhouse gas are trapped under the seafloor, and that’s a good thing. Around the coasts of the continents, where slopes sink down into the sea, tiny cages of ice trap methane gas, preventing it from escaping and bubbling up into the atmosphere.

While rarely in the news, these ice cage formations, known as methane clathrates, have garnered attention because of their potential to affect climate change. During offshore drilling, methane ice can get stuck in pipes, causing them to freeze and burst. The 2010 Deepwater Horizon oil spill is thought to have been caused by a buildup of methane clathrates.

But until now, the biological process behind how methane gas remains stable under the sea has been almost completely unknown. In a breakthrough study, a cross-disciplinary team of Georgia Tech researchers discovered a previously unknown class of bacterial proteins that play a crucial role in the formation and stability of methane clathrates.

A team led by Jennifer Glass, associate professor in the School of Earth and Atmospheric Sciences, and Raquel Lieberman, professor and Sepcic-Pfeil Chair in the School of Chemistry and Biochemistry, showed that these novel bacterial proteins suppress the growth of methane clathrates as effectively as commercial chemicals currently used in drilling, but are non-toxic, eco-friendly, and scalable. Their study, funded by NASA, informs the search for life in the solar system, and could also increase the safety of transporting natural gas.

The research, published in the journal PNAS Nexus, underscores the importance of fundamental science in studying Earth’s natural biological systems and highlights the benefits of collaboration across disciplines.

“We wanted to understand how these formations were staying stable under the seafloor, and precisely what mechanisms were contributing to their stability,” Glass said. “This is something no one has done before.”

Sifting Through Sediment

The effort started with the team examining a sample of clay-like sediment that Glass acquired from the seafloor off the coast of Oregon.

Glass hypothesized that the sediment would contain proteins that influence the growth of methane clathrate, and that those proteins would resemble well-known antifreeze proteins in fish, which help them survive in cold environments.

But to confirm her hypothesis, Glass and her research team would first have to identify protein candidates out of millions of potential targets contained in the sediment. They would then need to make the proteins in the lab, though there was no understanding of how these proteins might behave. Also, no one had worked with these proteins before.

Glass approached Lieberman, whose lab studies the structure of proteins. The first step was to use DNA sequencing paired with bioinformatics to identify the genes of the proteins contained in the sediment. Dustin Huard, a researcher in Lieberman’s lab and first author of the paper, then prepared candidate proteins that could potentially bind to the methane clathrates. Huard used X-ray crystallography to determine the structure of the proteins.

Creating Seafloor Conditions in the Lab

Huard passed off the protein candidates to Abigail Johnson, a former Ph.D. student in Glass’ lab and co-first author on the paper, who is now a postdoctoral researcher at the University of Georgia. To test the proteins, Johnson formed methane clathrates herself by recreating the high pressure and low temperature of the seafloor in the lab. Johnson worked with Sheng Dai, an associate professor in the School of Civil and Environmental Engineering, to build a unique pressure chamber from scratch.

Johnson placed the proteins in the pressure vessel and adjusted the system to mimic the pressure and temperature conditions required for clathrate formation. By pressurizing the vessel with methane, Johnson forced methane into the droplet, which caused a methane clathrate structure to form.

She then measured the amount of gas that was consumed by the clathrate — an indicator of how quickly and how much clathrate formed — and did so in the presence of the proteins versus no proteins. Johnson found that with the clathrate-binding proteins, less gas was consumed, and the clathrates melted at higher temperatures.

Once the team validated that the proteins affect the formation and stability of methane clathrates, they used Huard's protein crystal structure to carry out molecular dynamics simulations with the help of James (JC) Gumbart, professor in the School of Physics. The simulations allowed the team to identify the specific site where the protein binds to the methane clathrate.

A Surprisingly Novel System

The study unveiled unexpected insights into the structure and function of the proteins. The researchers initially thought the part of the protein that was similar to fish antifreeze proteins would play a role in clathrate binding. Surprisingly, that part of the protein did not play a role, and a wholly different mechanism directed the interactions.

They found that the proteins do not bind to ice, but rather interact with the clathrate structure itself, directing its growth. Specifically, the part of the protein that had similar characteristics to antifreeze proteins was buried in the protein structure, and instead played a role in stabilizing the protein.

The researchers found that the proteins performed better at modifying methane clathrate than any of the antifreeze proteins that had been tested in the past. They also performed just as well as, if not better than, the toxic commercial clathrate inhibitors currently used in drilling that pose serious environmental threats.

Preventing clathrate formation in natural gas pipelines is a billion-dollar industry. If these biodegradable proteins could be used to prevent disastrous natural gas leaks, it would greatly reduce the risk of environmental damage.

“We were so lucky that this actually worked, because even though we chose these proteins based on their similarity to antifreeze proteins, they are completely different,” Johnson said. “They have a similar function in nature, but do so through a completely different biological system, and I think that really excites people.”

Methane clathrates likely exist throughout the solar system — on the subsurface of Mars, for example, and on icy moons in the outer solar system, such as Europa. The team’s findings indicate that if microbes exist on other planetary bodies, they might produce similar biomolecules to retain liquid water in channels in the clathrate that could sustain life.

“We’re still learning so much about the basic systems on our planet,” Huard said. “That’s one of the great things about Georgia Tech — different communities can come together to do really cool, unexpected science. I never thought I would be working on an astrobiology project, but here we are, and we’ve been very successful.”

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Citation: Dustin J E Huard, et al. Molecular basis for inhibition of methane clathrate growth by a deep subsurface bacterial protein, PNAS Nexus, Volume 2, Issue 8, August 2023.

DOI: https://doi.org/10.1093/pnasnexus/pgad268

Funding: National Aeronautics & Space Administration, National Science Foundation, National Institutes of Health, American Chemical Society Petroleum Research Fund

Georgia Tech co-authors included Zixing Fan, Ph.D. student, and two undergraduates, Lydia Kenney (now a Ph.D. student at Northwestern University) and Manlin Xu (now a Ph.D. student in the MIT-Woods Hole Oceanographic Institution Joint Program). Ran Drori, associate professor of chemistry at Yeshiva University, also contributed.

Natalie Stingelin, chair of Georgia Tech’s School of Materials Science and Engineering, has been elected to the European Academy of Sciences (EURASC). The honor is bestowed upon the most distinguished European scholars and engineers for their research and contributing to the development of advanced technologies. Each honoree also displays a strong commitment to promoting science and technology in Europe.

Stingelin is recognized for her significant contributions in the broader areas of polymer physics, functional macromolecular materials, and organic electronics and photonics as well as her strong devotion and conviction to generating a notable impact on the wider engineering field as a role model for women in STEM.

Read the full story on the College of Engineering website.

Each year, exposure to airborne particulate matter known as PM2.5 (particles with a diameter smaller than 2.5 micrometers) leads to millions of premature deaths worldwide. Organic aerosols are the dominant constituents of PM2.5 in many locations around the world. Historically, the chemical complexity of organic aerosols has made it difficult to gauge their toxicity level.

But a study led by researchers at Georgia Institute of Technology has advanced understanding of both the chemical composition of PM2.5 and the reaction of alveolar cells of the lungs exposed to this pollution, highlighting the growing threat posed to human health.

Published in Environmental Science and Technology, the study shows that oxidized organic aerosols (OOA) are the most toxic type of organic aerosols in PM2.5.

“Oxidized organic aerosols are the most abundant type of organic aerosols worldwide,” said Nga Lee (Sally) Ng, Love Family Professor in Georgia Tech’s School of Chemical and Biomolecular Engineering and School of Earth and Atmospheric Sciences. “For example, when wildfire smoke reacts in the atmosphere, it generates OOA.”

Measurement Techniques

As the researchers used advanced techniques such as mass spectrometry to analyze the chemical composition of PM2.5 in Atlanta, Georgia, they simultaneously measured the production of reactive oxygen species (ROS) in alveolar cells resulting from pollution exposure.

ROS are molecules that can cause oxidative stress and damage to our cells, potentially leading to various health problems, including cardiopulmonary diseases.

To understand the mechanisms behind PM2.5-induced oxidative stress, the researchers employed cellular assays, which allowed them to measure both chemically and biologically generated ROS.

The study revealed that highly unsaturated species containing carbon-oxygen double bonds and aromatic rings within OOA are major drivers of cellular ROS production, advancing understanding of the chemical features of ambient organic aerosols that make them toxic.

Wildfires Are Growing Source

As the contribution from fossil-fuel sources to organic aerosols formation has declined in the United States in recent decades due to reduction strategies, the relative importance of other sources has increased, said Fobang Liu, lead author of the study.

“For example, biomass burning is expected to become a more important source of OOA with the increasing trend of wildfires,” added Liu, a former postdoctoral researcher in Ng’s lab at Georgia Tech who is now an associate professor at Xi’an Jiaotong University in China.

A major chemical characteristic of OOA formed from biomass burning is the high fraction of oxygenated aromatic compounds. “Hence, this work highlights that organic aerosols can become more toxic in the future,” he said.

Continued Collaboration

According to the researchers, their findings underscore the need for continued collaboration among the fields of atmospheric chemistry, toxicology, epidemiology, and biotechnology to tackle the global air pollution crisis.

“OOA are a surrogate of secondary organic aerosols. Secondary organic aerosols  are ubiquitous and abundant in the atmosphere, we need to understand their sources and chemical processing when formulating effective strategies to mitigate PM2.5 health impacts,” said Professor Ng.

“Future work should continue to investigate the health impacts of different PM2.5 components, particularly secondary organic aerosols formed from precursors emitted during incomplete combustion processes of fossil and biomass fuels,” she said.

Different regions may have varying types of organic aerosols due to diverse emission sources and atmospheric conditions. Therefore, long-term measurement of organic aerosol types over a wide range of geographical areas will be important to advance understanding of health impacts, the researchers emphasized.

Such work is being conducted by the Atmospheric Science and Chemistry mEasurement NeTwork (ASCENT), a $12 million advanced aerosol measurement network of 12 sites around the United States that is led by Professor Ng.

CITATION: Fobang Liu, Taekyu Joo, Jenna C. Ditto, Maria G. Saavedra, Masayuki Takeuchi, Alexandra J. Boris, Yuhan Yang, Rodney J. Weber, Ann M. Dillner, Drew R. Gentner, Nga L. Ng., “Oxidized and unsaturated: key organic aerosol traits associated with cellular reactive oxygen species production in the southeastern United States,” Environmental Science and Technology, 10.1021/acs.est.3c03641, 2023

A new $20.5 million Department of Energy project will establish a direct air capture hub in northern Mobile County, Alabama. 

Carbon dioxide (CO2), the primary pollutant from emissions past and present, stays in the atmosphere for hundreds of years, leading to climate change and its many consequences. Cleaning up these legacy emissions is an essential step in the creation of a sustainable, low-carbon economy. Direct Air Capture (DAC) is an innovative solution that captures CO2 directly from the air and reduces its levels in the atmosphere. The CO2 is then stored safely and securely or utilized to make value-added products.

The Georgia Institute of Technology collaborated with the Southern States Energy Board and its partners in the deployment of a direct air capture hub in Mobile County, Alabama. Known as the Southeast DAC (SEDAC) Hub, the project is funded by the U.S. Department of Energy’s Office of Fossil Energy and Carbon Management and will deploy cutting-edge DAC technologies to capture CO2 from the air. Steered by Joe Hagerman, director of NEETRAC, and Matthew Realff, professor in the School of Chemical and Biomolecular Engineering, David Wang Sr. Fellow, and initiative lead for circular carbon economy at the Strategic Energy Institute (SEI), the team will serve the educational, workforce, and community development functions in the project that is led by the Southern States Energy Board. Other partners include 8 Rivers, Aircapture, Crescent Resource Innovation, ENTECH Strategies, Mitternight, RTI International, the University of Alabama, and the University of South Alabama. Stakeholders include Southern Company and its Alabama Power Company subsidiary, Tenaska Sequestration Solutions, and the Mobile Chamber of Commerce, among many others.  

“We are thrilled to partner with the U.S. Department of Energy and the Southern States Energy Board in the SEDAC Hub project,” said Tim Lieuwen, SEI executive director, Regents’ Professor, and David S. Lewis Jr. Chair. “The project is important to the decarbonization efforts in the Southeast and will further amplify the Southeast’s leadership in the clean tech economy.”

Georgia Tech’s role will be supported by the Georgia Tech Center for Sustainable Communities Research and Education (SCoRE) and the Direct Air Capture Center (DirACC). Led by Jennifer Hirsch, adjunct associate professor in the School of City and Regional Planning, and senior director of Serve-Learn-Sustain at Georgia Tech, SCoRE engages faculty, students, and staff in long-term, strategic research and education collaborations with community partners, focusing on sustainability and connecting the historically underrepresented communities and students in the Atlanta region, the state of Georgia, and the Southeast. DirACC is the culmination of more than a decade of research at Georgia Tech to develop and evaluate materials, contactors, and processes that extract carbon dioxide directly from the atmosphere. DirACC creates a forum for collaborative research on negative emission technologies and DAC, bringing together researchers from across the Institute working in energy, sustainability, policy, and related fields. DirACC is jointly led by Christopher Jones, professor and John F. Brock III School Chair in the School of Chemical and Biomolecular Engineering, and Realff.

Mobile County is an ideal location to support the initial phases of a DAC hub. It is home to industrial facilities, large tracts of available land, and appropriate subsurface geology to support the creation of a sustainable, CO2-based economy. In addition, numerous opportunities exist to employ the region’s skilled workforce in pursuit of a variety of jobs beyond permanent storage in subsurface reservoirs (e.g., CO2 to fuels). The SEDAC Hub will not only help reduce local emissions, but also help create a carbon reduction ecosystem in the area — and the Gulf South more broadly.  

The project team has established robust community outreach and a two-way engagement program that includes a community advisory board composed of diverse local stakeholders; industry partners interested in decarbonization; and local community colleges, universities, and trade schools. The board will provide input to achieve community-supported DAC growth and guide the development of SEDAC’s community benefits plan.  

Visit the Project Page to learn more about the project and the team members.

Energy Research at Georgia Tech

The Georgia Institute of Technology is one of the top public research universities in the U.S., developing leaders who advance technology and improve the human condition. Georgia Tech has researchers working across the energy value chain and leads in scientific leadership in basic and applied science in carbon capture, industrial decarbonization, and related social sciences. Georgia Tech is consistently rated among the top universities in the nation for graduation of underrepresented minorities in engineering, physical sciences, and energy-related fields. Serving as a regional resource to help communities understand how they can transition to a clean energy economy, Georgia Tech is the southeastern leader in achieving regional impact through education and contributions to the community.

The water coming out of your faucet is safe to drink, but that doesn’t mean it’s completely clean. Chlorine has long been the standard for water treatment, but it often contains trace levels of disinfection byproducts and unknown contaminants. Georgia Institute of Technology researchers developed the minus approach to handle these harmful byproducts.

Instead of relying on traditional chemical addition (known as the plus approach), the minus approach avoids disinfectants, chemical coagulants, and advanced oxidation processes typical to water treatment processes. It uses a unique mix of filtration methods to remove byproducts and pathogens, enabling water treatment centers to use ultraviolet light and much smaller doses of chemical disinfectants to minimize future bacterial growth down the distribution system.

“The minus approach is a groundbreaking philosophical concept in water treatment,” said Yongsheng Chen, the Bonnie W. and Charles W. Moorman IV Professor in the School of Civil and Environmental Engineering. “Its primary objective is to achieve these outcomes while minimizing the reliance on chemical treatments, which can give rise to various issues in the main water treatment stream.”

Chen and his student Elliot Reid, the primary author, presented the minus approach in the paper, “The Minus Approach Can Redefine the Standard of Practice of Drinking Water Treatment,” in The American Chemical Society.

The minus approach physically separates emerging contaminants and disinfection byproducts from the main water treatment process using these already proven processes:

• Bank filtration withdraws water from naturally occurring or constructed banks like rivers or lakes. As the water travels through the layers of soil and gravel, it naturally filters out impurities, suspended particles, and certain microorganisms.
• Biofiltration uses biological processes to treat water by passing it through filter beds made of sand, gravel, or activated carbon that can support the growth of beneficial microorganisms, which in turn can remove contaminants.  
• Adsorption occurs when an adsorbent material like activated carbon is used to trap contaminants.
• Membrane filtration uses a semi-permeable membrane to separate particles and impurities from the main treatment process.

 

The minus approach is intended to engage the water community in designing safer, more sustainable, and more intelligent systems. Because its technologies are already available and proven, the minus approach can be implemented immediately.

It can also integrate with artificial intelligence (AI) to improve filtration’s effectiveness. AI can aid process optimization, predictive maintenance, faulty detection and diagnosis, energy optimization, and decision-support systems. AI models have also been able to reliably predict the origin of different types of pollution in source water, and models have also successfully detected pipeline damage and microbial contamination, allowing for quick and efficient maintenance.

 

“This innovative philosophy seeks to revolutionize traditional water treatment practices by providing a more sustainable and environmentally friendly solution,” Chen said. “By reducing the reliance on chemical treatments, the minus approach mitigates the potential risks associated with the use of such chemicals, promoting a safer water supply for both human consumption and environmental protection.”

CITATION: Elliot Reid, Thomas Igou, Yangying Zhao, John Crittenden, Ching-Hua Huang, Paul Westerhoff, Bruce Rittmann, Jörg E. Drewes, and Yongsheng Chen

Environmental Science & Technology 2023 57 (18), 7150-7161

DOI: 10.1021/acs.est.2c09389