SOUTHWESTRETORT
SEVENTY-SEVENTH YEAR
Published for the advancement of Chemists, Chemical Engineers and Chemistry in this area published by
April 2025
The Dallas-Fort Worth Section, with the cooperation of five other local sections of the American Chemical Society in the Southwest Region.
Vol. 77 (8) April 2025
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2025 ACS DFW Executive Committee
Chair: Denise Lynn Merkle, PhD
Chair-elect: Jonathan Dannatt, PhD
Past Chair: Rajani Srinivasan, PhD
Treasurer: Martha Gilchrist, MS
Secretary: Trey Putnam, PhD
Councilors:
MaryAnderson, PhD
Kirby Drake, JD
Linda Schultz, PhD
Rebecca Weber, PhD
Alternate Councilors:
Daniela Hutanu, PhD
Danny Tran, PhD
Yunxiang Li, PhD
From the ACS Press Room
Finding cancer’s ‘fingerprints’
“Electric-Field Molecular Fingerprinting to Probe Cancer"
ACS Central Science
Cancer diagnoses traditionally require invasive or labor-intensive procedures such as tissue biopsies. Now, research published in ACS Central Science reveals a method that uses pulsed infrared light to identify molecular profiles in blood plasma that could indicate the presence of certain common cancers. In this proof-of-concept study, blood plasma from more than 2,000 people was analyzed to link molecular patterns to lung cancer, extrapolating a potential “cancer fingerprint.”
Plasma extracted from whole blood samples (shown here) can reveal molecular signatures of lung cancer from a technique that uses ultra-short bursts of infrared light. angellodeco/Shutterstock.com
Plasma is the liquid portion of blood, depleted of any cells. It carries diverse molecules such as proteins, metabolites, lipids and salts throughout the body. Some molecules carried by blood plasma indicate potential health conditions. For example, unusually high levels of prostate-specific antigen are used to screen for prostate cancer. Theoretically, a medical test that measures a broad range of molecules could identify a pattern specific to different cancers, leading to quicker diagnoses and reduced costs. To look for telltale
chemical patterns of cancer, Mihaela Žigman and colleagues tested a technique called electric-field molecular fingerprinting that uses pulsed infrared light to profile complex molecular mixtures in blood plasma.
First, the researchers used the electric-field molecular fingerprinting technique to send ultra-short bursts of infrared light through plasma. They analyzed samples from 2,533 study participants, including people with lung, prostate, breast or bladder cancer and those without cancer. For each sample, they recorded the pattern of light emitted by the molecular mixtures in the plasma called an “infrared molecular fingerprint.”
Using these complex patterns from individuals with and without cancer, the researchers taught a machine learning model to identify molecular signatures associated with the four types of cancer. The computer model was tested on a separate subset of participants’ samples to see how well the model could perform on unseen test data. The analytical technique demonstrated a convincing level of accuracy (up to 81%) in detecting lung cancerspecific infrared signatures and differentiating them from control samples obtained from individuals without cancer. However, the computer model’s performance had lower success rates detecting the other three cancers. In the future, the researchers aim to expand and test the approach to identify additional cancer types and other health conditions.
"Laser-based infrared molecular fingerprint-
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From the ACS Press Room
Starch-based microplastics could cause health risks in mice, study finds
“Long-Term Exposure to Environmentally Realistic Doses of Starch-Based Microplastics Suggests Widespread Health Effects”
Journal of Agricultural and Food Chemistry
Wear and tear on plastic products releases small to nearly invisible plastic particles, which could impact people’s health when consumed or inhaled. To make these particles biodegradable, researchers created plastics from plant starch instead of petroleum. An initial study published in ACS’ Journal of Agricultural and Food Chemistry shows how animals consuming particles from this alternative material developed health problems such as liver damage and gut microbiome imbalances.
“Biodegradable starch-based plastics may not be as safe and health-promoting as originally assumed,” says Yongfeng Deng, the corresponding author of the study. Microplastics (plastic pieces less than 5 millimeters wide) are entering human bodies through contaminated water supplies, foods and drinks and even IV infusions. Scientists have linked plastic particles in the bloodstream and tissues to various health risks. For example, a study found that people with inflammatory bowel disease have more microplastics in their feces. Biodegradable plastics have been presented as a safer, more environmentally friendly alternative to traditional petroleum-based plastics. One of the most common types comes from starch, a carbohydrate found in potatoes, rice and
wheat. However, there is a lack of information on how starch-based biodegradable plastics affect the body. A team of researchers led by Deng tackled this issue by exploring these effects in animal trials.
Microscopic fragments from starch-based plastics (similar to those shown here) caused negative health impacts in mice, including changes to organ tissues, metabolic functions and gut microbiota diversity. Kononov Oleh/Shutterstock.com
The researchers compared three groups of five mice: one group consuming normal chow and two groups consuming food infused with starch-based microplastics. The doses (low and high) were calculated and scaled from what an average human is expected to consume daily. They fed the mice for 3 months and then assessed the animals’ organ tissues, metabolic functions and gut microbiota diversity. Mice exposed to the starch-based plastic particles had:
• Multiple damaged organs, including the liver and ovaries, with more pro-
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JUDGES NEEDED!
The 57thACS DFW MEETING-in-MINIATURE
East TexasA&M University Commerce, Texas Saturday,April 26, 2025
The 57th ACS DFW Meeting-in-Miniature will be held at the Science Building of East Texas A&M University from 8:30am-4:30pm on Saturday, April 26, 2025. There will be six parallel sessions, from 9am-12pm & 1-3:30pm, for over 90 presentations. We need ~15-20 judges. Half-day volunteers are welcome also. Lunch will be provided. If you are willing to serve, please register via the link https://www.tamuc.edu/acs-meeting-in-miniature by April 18, 2025. Thanks!
For further information on the meeting, please reach out to the following contacts:
Abstract: Dr. Bukuo Ni, Bukuo.Ni@tamuc.edu
General Info: Dr. Ben Jang, Ben.Jang@tamuc.edu
From the ACS Press Room
A step toward cleaner iron extraction using electricity
“Pathways to Electrochemical Ironmaking at Scale Via the Direct Reduction of Fe2O3 ”
ACS Energy Letters
Iron and its alloys, such as steel and cast iron, dominate the modern world, and there’s growing demand for iron-derived products. Traditionally, blast furnaces transform iron ore into purified elemental metal, but the process requires a lot of energy and emits air pollution. Now, researchers in ACS Energy Letters report that they’ve developed a cleaner method to extract iron from a synthetic iron ore using electrochemistry, which they say could become cost-competitive with blast furnaces.
"Identifying oxides which can be converted to iron metal at low temperatures is an important step in developing fully electrified processes for steelmaking," says Paul Kempler, the study’s corresponding author.
Electrochemical ironmaking isolates the metal by passing electricity through a liquid that holds iron-containing feedstocks. Compared to high-temperature blast furnaces, the electrochemical process could significantly reduce air pollution emissions, such as greenhouse gases, sulfur dioxide and particulate matter, and suggests considerable energy savings. Previously, Kempler and colleagues used this process to convert solutions containing solid iron(III) oxide particles and sodium hydroxide directly into elemental iron at temperatures around 176 to 194 degrees Fahrenheit (80 to 90 degrees Celsius). However, when some natural iron ores with irregularly sized, dense particles and impurities
were tested, this low-temperature process wasn’t selective enough. So, Kempler and a new team of researchers led by Anastasiia Konovalova and Andrew Goldman wanted to understand which iron ore-like feedstocks could support scalable growth of the process.
Adapted fromACS Energy Letters 2025, DOI: 10.1021/ acsenergylett.5c00166
First, the researchers prepared high surface area iron oxide particles with internal holes and connective cavities to investigate how the nanoscale morphology of the particles impacted the electrochemical reaction. Then, they converted some of these into micrometer-wide iron oxide particles to mimic the morphology of natural ores. These particles contained only a few trace impurities, such as carbon and barium. The team designed a spe-
Continued on page 25
It’s the shape and porosity, not the size, of metal oxide particles that matter for efficiency in electrochemical ironmaking.
From the ACS Press Room
Microplastics
in Bays along the Central Texas Coast
Environmental Science & Technology
There are trillions of microplastic particles, ranging in size from about one micrometer to a few millimeters, on Earth. Many of these particles end up in the oceans, where they disrupt nutrient cycles, are ingested by marine animals or transport pollutants. To better understand how microplastics accumulate and disperse in marine environments, new research published in ACS’ Environmental Science & Technology reflects efforts to locate hotspots areas with high concentrations of microplastics in Texas coastal bays.
Microplastics are lighter than similarly sized grains of sand and can be moved seaward by action from waves, storms or fishing. chayanuphol/Shutterstock.com
Coastal environments are important habitats for juvenile fish, oysters and protective salt marshes. Microplastics, which look like small grains or elongated filaments, can settle to the bottom of river mouths, estuaries (areas where freshwater mixes with salt water) and bays. There, they can accumulate in the sediment or float freely in the water, disturbing ecosystem balance. The problem is
particularly worrisome for the Texas bay systems, which have documented incidents of microplastic pollution. For example, the Formosa Plastic Corporation in Point Comfort, Texas, spilled billions of small plastic pellets, known as nurdles, into coastal waters in 2019. The presence of microplastics in estuarine environments is understudied, despite the critical nature of these locations. So, William Bailey and colleagues investigated estuaries and bays along the Texas coast to understand how many microplastics are being transported to the Gulf Coast, and later, the ocean.
To study microplastic accumulation and dispersion patterns, the team members sampled sediment in several locations along the Gulf shore. They identified plastic particles and plastic filaments using microscopy and spectroscopy techniques, as well as a process that sorts particles by size, shape and density. Overall, they found fewer microplastic particles than expected, given the documented incidences of nurdle spillage. The highest amounts of microplastics were by river mouths; but otherwise, the plastic particles were just as prevalent in deep water as shallow water closer to the shore.
The researchers reasoned that the lower-than -expected levels and even distribution of microplastics in coastal waters were a result of shrimp and oyster fishing, which scours the bottom of the bay and kicks up and redistributes sediments and microplastics. Winds are also capable of generating bottom-scraping waves, especially during strong Gulf storms.
Continued on page 26
From the ACS Press Room
A safe nuclear battery that could last a lifetime
SAN DIEGO, March 26, 2025 Sometimes cell phones die sooner than expected or electric vehicles don’t have enough charge to reach their destination. The rechargeable lithium-ion (Li-ion) batteries in these and other devices typically last hours or days between charging. However, with repeated use, batteries degrade and need to be recharged more frequently. Now, researchers are considering radiocarbon as a source for safe, small and affordable nuclear batteries that could last decades or longer without charging.
Su-Il In, a professor at Daegu Gyeongbuk Institute of Science & Technology, will present his results at the spring meeting of the American Chemical Society (ACS). ACS Spring 2025 is being held March 23-27; it features about 12,000 presentations on a range of science topics.
The frequent charging required for Li-ion batteries isn’t just an inconvenience. It limits the utility of technologies that use the batteries for power, such as drones and remotesensing equipment. The batteries are also bad for the environment: Mining lithium is energy-intensive and improper disposal of Li -ion batteries can contaminate ecosystems. But with the increasing ubiquity of connected devices, data centers and other computing technologies, the demand for long-lasting batteries is increasing.
And better Li-ion batteries are likely not the answer to this challenge. “The performance of Li-ion batteries is almost saturated,” says In, who researches future energy technologies. So, In and his team members are devel-
oping nuclear batteries as an alternative to lithium.
Nuclear batteries generate power by harnessing high-energy particles emitted by radioactive materials. Not all radioactive elements emit radiation that’s damaging to living organisms, and some radiation can be blocked by certain materials. For example, beta particles (also known as beta rays) can be shielded with a thin sheet of aluminum, making betavoltaics a potentially safe choice for nuclear batteries.
The researchers produced a prototype betavoltaic battery with carbon-14, an unstable and radioactive form of carbon, called radiocarbon. “I decided to use a radioactive isotope of carbon because it generates only beta rays,” says In. Moreover, a by-product from nuclear power plants, radiocarbon is inexpensive, readily available and easy to recycle. And because radiocarbon degrades very
Continued on page 17
A small dye-sensitized betavoltaic cell has radiocarbon on both the cathode and anode, which increases its energyconversion efficiency.
Su-Il In
From the ACS Press Room
continued
slowly, a radiocarbon-powered battery could theoretically last for millennia.
In a typical betavoltaic battery, electrons strike a semiconductor, which results in the production of electricity. Semiconductors are a critical component in betavoltaic batteries, as they are primarily responsible for energy conversion. Consequently, scientists are exploring advanced semiconductor materials to achieve a higher energy conversion efficiency a measure of how effectively a battery can convert electrons into usable electricity.
To significantly improve the energy conversion efficiency of their new design, In and the team used a titanium dioxide-based semiconductor, a material commonly used in solar cells, sensitized with a ruthenium-based dye. They strengthened the bond between the titanium dioxide and the dye with a citric acid treatment. When beta rays from radiocarbon collide with the treated ruthenium-based dye, a cascade of electron transfer reactions, called an electron avalanche, occurs. Then the avalanche travels through the dye and the titanium dioxide effectively collects the generated electrons.
The new battery also has radiocarbon in the dye-sensitized anode and a cathode. By treating both electrodes with the radioactive isotope, the researchers increased the amount of beta rays generated and reduced distancerelated beta-radiation energy loss between the two structures.
During demonstrations of the prototype battery, the researchers found that beta rays released from radiocarbon on both electrodes triggered the ruthenium-based dye on the an-
ode to generate an electron avalanche that was collected by the titanium dioxide layer and passed through an external circuit resulting in usable electricity. Compared to a previous design with radiocarbon on only the cathode, the researchers’ battery with radiocarbon in the cathode and anode had a much higher energy conversion efficiency, going from 0.48% to 2.86%.
These long-lasting nuclear batteries could enable many applications, says In. For example, a pacemaker would last a person’s lifetime, eliminating the need for surgical replacements.
However, this betavoltaic design converted only a tiny fraction of radioactive decay into electric energy, leading to lower performance compared to conventional Li-ion batteries. In suggests that further efforts to optimize the shape of the beta-ray emitter and develop more efficient beta-ray absorbers could enhance the battery’s performance and increase power generation.
As climate concerns grow, public perception of nuclear energy is changing. But it’s still thought of as energy only produced at a large power plant in a remote location. With these dual-site-source dye-sensitized betavoltaic cell batteries, In says, “We can put safe nuclear energy into devices the size of a finger.”
The research was funded by the National Research Foundation of Korea, as well as the Daegu Gyeongbuk Institute of Science & Technology Research & Development Program of the Ministry of Science and Information and Communication Technology of Korea.
13 students nominated for and completed the 2025 US National Chemistry Olympiad National Exam
The following 13 students were nominated for and completed the 2025 US National Chemistry Olympiad National Exam on Saturday,April 5, 2025, at Lewisville Hebron High School: (Student, school, teacher)
Celina Li*, The Hockaday School, Dr. Jen Fore
Everett Jin**, St. Mark’s School of Texas, Kenneth R. Owens
David Guo**, Highland Park High School, Wenzen Chuang
Henry Zhu, Highland Park High School, Wenzen Chuang
Zhanghe Xu, Frisco Liberty High School, Angela Montgomery
Kavya Athipatla, Southlake Carroll Senior High School, Julie McCurley
Sanabhi Gauraw, Plano East Senior High School, Karen Compton
Aristaa Bhardwaj, Allen High School, Daniel Perrault
Zihan Xu, Plano West Senior High School, Beverly Mahoney
Vishuddhi Makeshwaran, Frisco Centennial High School, Michael Krueger
Hasom Kim, Lewisville Flower Mound High School, Erin Charles
Kyle Alferink, Mansfield Frontier STEM Academy, David Bushdieker
Owen Xie, Frisco Emerson High School, Kimberly Lam
*Also a National Nominee in 2024
**Also a National Nominee in 2023 and 2024
Students chosen for this summer’s USNCO Study Camp will be announced by the end of May 2025.
It’s always a great pleasure to work with such outstanding high school chemistry students each spring!
Kathleen Holley, Ph. D.AP Physics C,AP Chemistry, Honors Physics
Science National Honor Society Sponsor
Big Blue Demo Crew Sponsor
UILScience Coach
Hebron High School
From the ACS Press Room
Fluorescent caves could explain how life persists in extraterrestrial environments
SAN DIEGO, March 25, 2025 Deep below Earth’s surface, rock and mineral formations lay hidden with a secret brilliance. Under a black light, the chemicals fossilized within shine in brilliant hues of pink, blue and green. Scientists are using these fluorescent features to understand how the caves formed and how life is supported in extreme environments, which may reveal how life could persist in faraway places, like Jupiter’s icy moon Europa.
The researchers will present their results at the spring meeting of the American Chemical Society (ACS). ACS Spring 2025 is being held March 23-27; it features about 12,000 presentations on a range of science topics.
Watch a Headline Science YouTube Short about this research.
Youtube ID: RMhmcEpZnGc
As it turns out, the chemistry in South Dakota’s Wind Cave is likely similar to places like Europa and easier to reach. This is why astrobiologist Joshua Sebree, a professor at the University of Northern Iowa, ended up hundreds of feet underground investigating the minerals and lifeforms in these dark, cold conditions.
“The purpose of this project as a whole is to try to better understand the chemistry taking place underground that’s telling us about how life can be supported,” he explains.
As Sebree and his students began to venture into new areas of Wind Cave and other caves
across the U.S., they mapped the rock formations, passages, streams and organisms they found. As they explored, they brought along their black lights (UV lights), too, to look at the minerals in the rocks.
Under the black light, certain areas of the caves seemed to transform into something otherworldly as portions of the surrounding rocks shone in different hues. Thanks to impurities lodged within the Earth millions of years ago chemistry fossils, almost the hues corresponded with different concentrations and types of organic or inorganic compounds. These shining stones often indicated where water once carried minerals down from the surface.
“The walls just looked completely blank and devoid of anything interesting,” says Sebree.
A section of South Dakota’s Wind Cave seen under normal white light (left image) transforms into something otherworldly when placed under UV light (right image).
Joshua Sebree
From the ACS Press Room
“But then, when we turned on the black lights, what used to be just a plain brown wall turned into a bright layer of fluorescent mineral that indicated where a pool of water used to be 10,000 or 20,000 years ago.”
Typically, to understand the chemical makeup of a cave feature, a rock sample is removed and taken back to the lab. But Sebree and his team collect the fluorescence spectra which is like a fingerprint of the chemical makeup of different surfaces using a portable spectrometer while on their expeditions. That way, they can take the information with them but leave the cave behind and intAnna Van Der Weide, an undergraduate student at the university, has accompanied Sebree on some of these explorations. Using the information collected during that fieldwork, she is building a publicly accessible inventory of fluorescence fingerprints to help provide an additional layer of information to the traditional cave map and paint a more complete picture of its history and formation.
Additional undergraduate students have contributed to the study. Jacqueline Heggen is further exploring these caves as a simulated environment for astrobiological extremophiles; Jordan Holloway is developing an autonomous spectrometer to make measurement easier and even possible for future extraterrestrial missions; and Celia Langemo is studying biometrics to keep explorers of extreme environments safe. These three stu-
dents are also presenting their findings at ACS Spring 2025.
Doing science in a cave is not without its challenges. For example, in the 48-degrees Fahrenheit (9-degrees Celsius) temperature of Minnesota’s Mystery Cave, the team had to bury the spectrometer’s batteries in handwarmers to keep them from dying. Other times, to reach an area of interest, the scientists had to squeeze through spaces less than a foot (30 centimeters) wide for hundreds of feet, sometimes losing a shoe (or pants) in the process. Or, they’d have to stand kneedeep in freezing cave water to take a measurement, and hope that their instruments didn’t go for an accidental swim.
But despite these hurdles, the caves have revealed a wealth of information already. In Wind Cave, the team found that manganeserich waters had carved out the cave and produced the striped zebra calcites within, which glowed pink under black light. The calcites grew underground, fed by the manganeserich water. Sebree believes that when these rocks shattered, since calcite is weaker than
Continued on Page 26
Several fluorescence measurements of a zebra calcite in Wind Cave were taken using portable spectrometers. Joshua Sebree
One of Sebree’s students, Jacqueline Heggen, showing off glowing formations within Wind Cave. Joshua Sebree
From the ACS Press Room
Making sturdy, semi-transparent wood with cheap, natural materials
SAN DIEGO, March 26, 2025 Can you imagine a smartphone with a wooden touchscreen? Or a house with wooden windows? Probably not unless you’ve heard of transparent wood. Made by modifying wood’s natural structure, this material has been proposed as a sturdy, eco-friendly plastic alternative. But wood’s biodegradability is often sacrificed in the process. Researchers are hoping to change that by creating transparent woods from almost entirely natural materials and making them electrically conductive.
The researchers will present their results at the spring meeting of the American Chemical Society (ACS). ACS Spring 2025 is being held March 23-27; it features about 12,000 presentations on a range of science topics.
. “In the modern day, plastic is everywhere, including our devices that we carry around. And it’s a problem when we reach the end of
that device’s life. It’s not biodegradable,” explains Bharat Baruah, a professor of chemistry at Kennesaw State University and the presenter of this research. “So, I asked, what if we can create something that’s natural and biodegradable instead?”
Baruah became interested in transparent woods thanks to his outside-of-work pursuits namely, his woodworking hobby. But he realized that the transparent woods reported by other scientists used materials such as epoxies, a form of plastic, for strength. To find natural materials that would keep wood sturdy and stable over time, he again turned to his personal experiences. Growing up in the state of Assam in northeastern India, Baruah encountered buildings that had been standing for centuries long before the modern-day version of cement was invented. Instead, ancient masons created cement by mixing sand with sticky rice and egg whites. Baruah hypothesized that those same materials might be perfect for incorporating strength and stability into his transparent woods.
Wood has three components: cellulose, hemicellulose and lignin. To make it transparent, the lignin and hemicellulose are removed, leaving behind a porous, paper-like network of cellulose. Then, a colorless material fills in those pores, also restoring some rigidity.
Joined by Ridham Raval, an undergraduate student at the university, Baruah transformed pieces of balsa wood into natural, semiContinued on Page 18
This slice of semi-transparent wood is made with natural materials and could be used in applications from wearable sensors to energy-efficient windows.
Bharat Baruah
transparent woods by pulling out the lignin and hemicellulose using a vacuum chamber and chemicals, including sodium sulfite (a delignifying agent), sodium hydroxide (a version of lye) and diluted bleach. Then, the pores were refilled by soaking them in an egg white and rice extract mixture, along with a curing agent called diethylenetriamine to keep the material see-through. The researchers say that these reagents, when used in small amounts, such as in this experiment, pose little threat to the environment.
In the end, the team was left with semitransparent slices of wood that were durable and flexible. The team next investigated some potential applications for their engineered woods, including as a replacement for glass windows. Again, Baruah tapped into his woodworker skills and renovated a birdhouse into a tiny, one-windowed, insulated home. To test the modernized abode’s energy efficiency, he put the birdhouse under a heat lamp and placed a temperature gauge inside. The temperature inside the house was between 9 to 11 degrees Fahrenheit (5 to 6 degrees Celsius) cooler when transparent wood was used than when glass was, suggesting that this new material could serve as an energy-efficient alternative to glass in windows.
To further expand the transparent wood’s potential applications, the team also incorporated silver nanowires into certain samples. This addition allowed the wood to conduct electricity, which could be useful for wearable sensors or coatings for solar cells. Silver nanowires aren’t biodegradable, but the team hopes to conduct further experiments using other conductive materials like graphene to maintain their fully natural transparent woods.
Though additional research is needed to boost the transparency of the woods, Baruah
is happy that this initial step used natural and inexpensive materials. “I want to send a message to my undergraduate students that you can do interesting research without spending thousands of dollars,” he concludes.
The research was funded by Kennesaw State University and Purafil Inc., an air filtration manufacturer.
Dr. James L. Marshall, son of Madison Lincoln Marshall and Irene VanEman Marshall, native of Denton, TX, passed away peacefully on March 28, 2025 at age 84. He earned his B.S. in chemistry at Indiana University in 1962, and his Ph.D. in organic chemistry at Ohio State University in 1966. The following year Dr. Marshall joined the Department of Chemistry at the North Texas State University (now University of North Texas, UNT). At UNT he was involved in conformational analysis utilizing carbon-13 nuclear magnetic resonance coupling constants. During the early 1980s Dr. Marshall spent six years at Motorola, Inc., Ft. Worth, where he developed the laboratory facilities for the Advanced Manufacturing Technology Program. In 1987 he returned to the University of North Texas where he conducted materials research; and in the 1990s he initiated research in chemical history. His research at UNT has resulted in over 250 publications, including a reference book on NMR, and several books on the history of chemistry and laboratory chemistry. At UNT Dr. Marshall served as Director of Industry-University Cooperative Research Center, Director of the Center for Materials Characterization, and Chairman of the Department of Chemistry. He also taught countless students to love chemistry. Always the jokester, he would ingest maple syrup disguised in a motor oil bottle or drink liquid nitrogen, always to catch his students’ attention and show them learning is fun. Students loved Jim in class, and he also was chosen as an Honor Professor by The UNT Student Association for 1988-1989 school year, a “Top Prof” by Mortar Board in 1989, and an Outstanding Faculty Member by Sigma Phi Epsilon in 1995.
Dr. Marshall has served as Chairman of the Dallas-Ft. Worth Section of the American Chemical Society, and during the period 1995-2003 was Managing Editor of The Southwest Retort, an ACS publication of the Southwest Regional. He has served as an ACS national tour speaker for many years. He married his late wife Virginia R. (Jenny) Marshall in 1998, he and his wife developed an extensive work, "Rediscovery of the Elements," and in 2010 completed their work and prepared a DVD describing their travels and the results of their research. Their research received international acclaim, for example being reviewed in Nature (2005, 436(25) 1082-1083) and their work also won “Best Paper Award” in the Bulletin for the History of Chemistry in 2004. Dr. Marshall has created the only collection of elements in the world that contains not only all the natural elements, but authentic samples of minerals from the original sites that he and Jenny collected over the 16 years of their collaboration, viewable with explanations through his You Tube site https://www.youtube.com/@rediscoveryoftheelements5753 .
Service to the ACS and chemical research was recognized by his inclusion in the 2011 class of Fellows of the American Chemical Society. He retired from UNT in 2017 as an Emeritus Professor and continued his extensive writings on the history of the chemical elements. In August of 2024, he, along with his late wife Jenny, received the American Chemical Society Lambert Award for his outstanding achievements in the history of chemistry for their work on the Re-
discovery of the Elements.
The project on the Rediscovery of the Elements resulted in a massive archive produced by all the modalities of the modern historian. The original work was published as a series of articles in The Hexagon, the official journal of the professional chemistry fraternity Alpha Chi Sigma. The first one was: “Rediscovery of the Elements: Tellurium and Faţa Băii (Fascebanya), Romania,” James L. Marshall and Virginia R. Marshall, The Hexagon of Alpha Chi Sigma, 91, No. 3, Fall, 43-45, (2000). The last one was: “Rediscovery of the Elements. The Alchemical Journey. Part 3.” J. L. Marshall and V. R. Marshall, The Hexagon of Alpha Chi Sigma,” 112(1), 10-13, (2021). More than 50 articles in all were published. In order to make the full corpus more available, the Marshalls produced a DVD containing photographs and maps of the discovery sites. The initial version was published in 2010; it has since been updated and is now available as a third edition (2021) that can be accessed on the internet at https://sites.chemistry.unt.edu/~jimm/ REDISCOVERY%206-10-2021/
As Jim often said, “And, when you want something, all the universe conspires in helping you to achieve it.”― Paulo Coelho, The Alchemist; and the universe conspired to allow himand Jenny to achieve the Rediscovery dream.
Among his many hobbies included bird studying, flying, and hiking, and he was an avid naturalist. James was an active flight instructor (private; instrument; twin) for decades, and among his students are included American Airline pilots. James has hiked the Grand Canyon several times, including all the way twice - once with his son Cristopher. In his high school and college years, he was active in music – he was First Chair tuba in the state of Alabama, 1957 and 1958; and during the years 1959-1960 he was the tuba player in the Charlotte Symphony in North Carolina.
Dr. Marshall was preceded in death by his fourth wife, Jenny Marshall, and two siblings, Drs. William and Ernest Marshall. He is survived by his sister Dr. Madilyn Fletcher and his two heartbroken children, Cristopher Marshal. M.Ed. and Dr. Pamela A. Marshall (to whom he instilled his love of science), their spouses (Cindy Marshall and David Lelsz) and three amazing grandchildren, Griffin Marshall, Garyn Marshall, and Stephanie Lelsz.
In lieu of flowers, please donate to the Alpha Chi Sigma Educational Foundation (https:// foundation.alphachisigma.org ), Alpha Chi Sigma (https://www.alphachisigma.org/donate ), the History Division of the American Chemical Society (https://acshist.scs.illinois.edu/ index.php ), or your favorite scientific support society or scientific charity.
Please join us for a Celebration of Life on May 19th, at 11am at Bill DeBerry Funeral Directors in Denton, TX, 2025 W University Dr., Denton, TX 76201.
From the ACS Press Room
Chewing gum can shed microplastics into saliva, pilot study finds
SAN DIEGO, March 25, 2025 Plastic is everywhere. And many products we use in everyday life, such as cutting boards, clothes and cleaning sponges, can expose people to tiny, micrometer-wide plastic particles called microplastics. Now, chewing gum could be added to the list. In a pilot study, researchers found that chewing gum can release hundreds to thousands of microplastics per piece into saliva and potentially be ingested.
The researchers will present their results at the spring meeting of the American Chemical Society (ACS). ACS Spring 2025 is being held March 23-27; it features about 12,000 presentations on a range of science topics.
“Our goal is not to alarm anybody,” says Sanjay Mohanty, the project’s principal investigator and an engineering professor at the University of California, Los Angeles (UCLA). “Scientists don’t know if microplastics are unsafe to us or not. There are no human trials. But we know we are exposed to
plastics in everyday life, and that’s what we wanted to examine here.”
Animal studies and studies with human cells show that microplastics could cause harm, so while we wait for more definitive answers from the scientific community, individuals can take steps to reduce their exposure to microplastics.
Scientists estimate that humans consume tens of thousands of microplastics (between 1 micrometer- and 5 millimeters-wide) every year through foods, drinks, plastic packaging, coatings, and production or manufacturing processes. Yet, chewing gum as a potential source of microplastics hasn’t been widely studied, despite the candy’s worldwide popularity. So, Mohanty and a graduate student in his lab, Lisa Lowe, wanted to identify how many microplastics a person could potentially ingest from chewing natural and synthetic gums.
Chewing gums are made from a rubbery base, sweetener, flavorings and other ingredients. Natural gum products use a plant-based polymer, such as chicle or other tree sap, to achieve the right chewiness, while other products use synthetic rubber bases from petroleum-based polymers.
“Our initial hypothesis was that the synthetic gums would have a lot more microplastics because the base is a type of plastic,” says Lowe, who started the project as an undergraduate intern at UCLA and the presenter of this research.
Both natural and synthetic chewing gums released microplastics into saliva in a pilot study. New Africa/Shutterstock.com
From the ACS Press Room
The researchers tested five brands of synthetic gum and five brands of natural gum, all of which are commercially available. Mohanty says they wanted to reduce the human factor of varied chewing patterns and saliva, so they had seven pieces from each brand all chewed by one person.
In the lab, the person chewed the piece of gum for 4 minutes, producing samples of saliva every 30 seconds, then a final mouth rinse with clean water, all of which got combined into a single sample. In another experiment, saliva samples were collected periodically over 20 minutes to look at the release rate of microplastics from each piece of gum. Then, the researchers measured the number of microplastics present in each saliva sample. Plastic particles were either stained red and counted under a microscope or analyzed by Fourier-transform infrared spectroscopy, which also provided the polymer composition.
Lowe measured an average of 100 microplastics released per gram of gum, though some individual gum pieces released as many as 600 microplastics per gram. A typical piece of gum weighs between 2 and 6 grams, meaning a large piece of gum could release up to 3,000 plastic particles. If the average person chews 160 to 180 small sticks of gum per year, the researchers estimated that could result in the ingestion of around 30,000 microplastics. If the average person consumes tens of thousands of microplastics per year, gum chewing could greatly increase the ingested amount.
“Surprisingly, both synthetic and natural gums had similar amounts of microplastics released when we chewed them,” says Lowe. And they also contained the same polymers:
polyolefins, polyethylene terephthalates, polyacrylamides and polystyrenes. The most abundant polymers for both types of gum were polyolefins, a group of plastics that includes polyethylene and polypropylene.
Most of the microplastics detached from gum within the first 2 minutes of chewing. But Mohanty says they weren’t released because of enzymes in saliva breaking them down. Rather, the act of chewing is abrasive enough to make pieces flake off. And after 8 minutes of chewing, 94% of the plastic particles collected during the tests had been released. Therefore, Lowe suggests that if people want to reduce their potential exposure to microplastics from gum, they chew one piece longer instead of popping in a new one. The study was limited to identifying microplastics 20-micrometers-wide or larger because of the instruments and techniques used. It’s likely, Mohanty says, that smaller plastic particles were not detected in saliva and that additional research is needed to assess the potential release of nano-sized plastics from chewing gum.
“The plastic released into saliva is a small fraction of the plastic that’s in the gum,” concludes Mohanty. “So, be mindful about the environment and don’t just throw it outside or stick it to a gum wall.” If used gum isn’t properly thrown away, it’s another source of plastic pollution to the environment, too.
The research was funded by UCLA and the University of Hawaii Maximizing Access to Research Careers program, which is funded by the National Institutes of Health and the California Protection Council.
The study’s experimental approach was approved by the Internal Review Board at UCLA.
From the ACS Press Room
Guardians of the vineyard: Canines and chemistry team up to combat powdery mildew
SAN DIEGO, March 23, 2025 Dogs have many jobs but one you may not expect is identifying grapevines coated in a destructive and highly contagious fungus. Although dogs can detect serious vine infections by smell, scientists don’t know exactly what odor molecules are triggering the response. Researchers are now analyzing volatile chemicals emanating from grape leaves infected by a fungus called powdery mildew with the goal of improving training for vineyard canines.
Nayelly Rangel, a graduate student at Texas Tech University, will present the team’s results at the spring meeting of the American Chemical Society (ACS). ACS Spring 2025 is being held March 23-27; it features about 12,000 presentations on a range of science topics.
Watch a Headline Science YouTube Short about this research.
Youtube ID: l2mwNPeCBJA
“Powdery mildew is one of the most contagious diseases that affects grapevine plants,” says Rangel. “It reduces plant growth, fruit quality and quantity, and it can lead to a decline in wine quality.”
The current method to identify an infection relies on humans looking for tell-tale patches of grey powder along plant leaves. But, by then, the condition is usually serious and requires large amounts of fungicide to eradicate. Past research showed that dogs can
identify powdery mildew by smell. But not much is known about the chemistry of what these animals smell, or whether the plants’ odor profile changes as the infection progresses.
Emilio
“Our four-legged friends don’t talk, so we’re trying to understand what they are encountering when they’re sniffing,” says Paola PradaTiedemann, a professor of forensic science at Texas Tech University who is leading the study. So, the researchers set out to identify which volatile organic compounds, or airborne scents, grapevine leaves give off at different stages of powdery mildew infection.
First, the team needed a technique that would keep leaf samples intact for dog training. So, they placed a leaf inside a vial and inserted a tiny absorptive fiber into the vial to pick up chemicals from the air above a leaf. From
By “bridging the canine to chemistry,” researchers aim to find a more efficient solution for training dogs to identify powdery mildew a widespread and damaging disease for vineyards.
100/Shutterstock.com
From the ACS Press Room
there, the researchers characterized the volatile organic compounds (VOCs) stuck to the fiber by inserting it directly into a gas chromatograph-mass spectrometer.
“Our approach is unique because we’re testing the exact location where a canine sniffs the grape leaf,” says Rangel. “So, we’re analyzing the same airspace in both scenarios, whether we’re in the chemistry lab or the canine lab.”
So far, the team has optimized their process from the VOCs emitted from healthy leaves. Initial results from comparisons of healthy and fungus-impacted grapes revealed that the baseline odors emitted from healthy leaves include more acidic odor compounds than sick ones. In fact, healthy leaves released fewer vapors over time, says Rangel, in contrast to sick leaves that expelled more VOCs as the infection grew.
Next, the researchers will analyze the chemical composition of what’s wafting off the leaves at different stages of infection. Once they’ve identified a few key molecules, they will present each one individually to the ca-
nines, measure the animals’ responses to each, and test the smallest amount needed for detection. Like how certain scents, such as vinegar’s, are strong in small amounts, the researchers think that dogs may pick up on certain VOCs more easily than others. Using those compounds for training could enable more sensitive and accurate mildew identification, especially early-stage infections.
“The ultimate goal is to move away from the visual diagnosis of mildew to odor diagnosis as the gold standard,” says PradaTiedemann. “Even when we can’t see it ourselves, the dog sitting next to a plant can tell you with their nose, ‘uh oh, that vine’s starting to go.’”
By “bridging the canine to chemistry,” as Prada-Tiedemann says, the team wants to find a more efficient solution for protecting grapevines from a widespread and damaging disease. After all, she adds, “We all want good wine!”
The researchers report no external funding for this work.
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From the ACS Press Room
continued
Finding cancer’s ‘fingerprints’
from page 5
ing detects cancer, demonstrating its potential for clinical diagnostics,” Žigman says. “With further technological developments and independent validation in sufficiently powered clinical studies, it could establish generalizable applications and translate into clinical practice advancing the way we diagnose and screen for cancer today.”
The authors acknowledge support from the Ludwig Maximilian University of Munich Centre for Advanced Laser Applications (CALA) and the Researchers Supporting Project.
Some authors have filed a patent application for this technology.
Starch-based microplastics
Continued from page 6
nounced damage in the high-dose group. However, mice eating normal chow showed normal organ tissue biopsies.
• Altered glucose management, including significant abnormality in triglycerides (a type of fat) and disruption in molecular biomarkers associated with glucose and lipid metabolism, compared to mice fed normal chow.
• Dysregulated genetic pathways and specific gut microbiota imbalances, which the researchers suggest could al-
ter microplastic-consuming animals’ circadian rhythms.
“Prolonged low-dose exposure to starchbased microplastics can lead to a broad spectrum of health impacts, particularly perturbing circadian rhythms and disrupting glucose and lipid metabolism,” says Deng. However, the researchers acknowledge that because this is one of the first studies examining the impacts of consuming starchbased microplastics, further research is needed to understand how these biodegradable particles break down in the body.
The authors acknowledge funding from the Natural Science Foundation of China, the Jiangsu Province Young Science and Technology Talent Support Program, the Joint Fund of Departments and Schools, the Start -up Research Fund, and the Zhishan Young Scholars Fund of Southeast University by the Fundamental Research Funds for the Central Universities.
A step toward cleaner iron extraction
Continued from page 8
cialized cathode to pull iron metal from a sodium hydroxide solution containing the iron oxide particles as current passed through it.
In experiments, dense iron oxides were reduced, or converted into elemental iron, most selectively at a current density of 50 milliamperes per square centimeter, similar
From the ACS Press Room
continued
to rapidly charging lithium-ion batteries. Conversely, loose particles with higher porosity, and thus higher surface area, facilitated more efficient electrochemical iron production, as compared to those made to resemble the less porous natural iron ore hematite.
The researchers evaluated the potential cost of their electrochemical ironmaking method. At the current density used in the experiments, they estimated that iron could be produced at less than $600 per metric ton ($0.60 per kilogram), which is comparable to traditional ironmaking. The study showed that much higher current densities, up to 600 milliamperes per square centimeter, similar to those used in industrial electrolysis cells, could be achieved when using particles with nanoscale porosity. Further advances in electrochemical cell design and techniques to make iron oxide feedstocks more porous will be required before the technology sees commercial adoption.
The authors acknowledge funding from the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences.
Microplastics in Bays Contin-
ued from page 9
And because microplastics are less dense than natural sediments, they’re more likely to be transported by big waves out of the bays and into the Gulf, and eventually, the open ocean.
The team’s future work will incorporate their microplastic transport and deposition data into numerical models that “can be applied to the Gulf shore and other understudied, high-risk
areas to effectively inform conservation efforts and pollution mitigation strategies,” says Bailey.
The authors acknowledge funding from the Matagorda Bay Mitigation Trust and the Jackson School of Geosciences at the University of Texas at Austin.
Fluorescent caves
Continued from page 14
the limestone also comprising the cave, the calcite worked to expand the cave too. “It’s a very different cave forming mechanism than has previously been looked at before,” he says.
And the unique research conditions have provided a memorable experience to Van Der Weide. “It was really cool to see how you can apply science out in the field and to learn how you function in those environments,” she concludes.
In the future, Sebree hopes to further confirm the accuracy of the fluorescence technique by comparing it to traditional, destructive techniques. He also wants to investigate the cave water that also fluoresces to understand how life on Earth’s surface has affected life deep underground and, reconnecting to his astrobiological roots, understand how similar, mineral-rich water may support life in the far reaches of our solar system.
The research was funded by NASA and the Iowa Space Grant Consortium.
From the Editor
Meeting-in-Miniature: next Saturday in Commerce at East Texas A&M. Be there if you can!
Congratulations to the students who were nominated for and completed the 2025 US National Chemistry Olympiad National Exam on Saturday, April 5, 2025, at Lewisville Hebron High School.
Jim Marshall of UNT passed away at the end of March at age 84. His Celebration of Life will beon May 19th, at 11am at Bill DeBerry Funeral Directors in Denton, TX, 2025 W University Dr., Denton, TX 76201.
Why, you ask, did I include three papers on microplastics? Microplastics are "synthetic solid particles or polymeric matrices, with regular or irregular shape and with size ranging from 1 μm to 5 mm, of either primary or secondary manufacturing origin, which are insoluble in water." And they are everywhere...there is a good article in Harvard Medicine which covers the topic succinctly: https://magazine.hms.harvard.edu/articles/microplastics-everywhere
