With a passion for polymer research and teaching, Arthi Jayaraman of the University of Delaware often finds herself wearing a lot of hats, figuratively, at least.

“My research has me putting on different hats,” said Jayaraman, Centennial Term Professor for Excellence in Research and Education in the College of Engineering. “Sometimes I have to put on the physicist hat, sometimes the chemist hat, and always the engineering hat.”

In the past year, professional societies in all three disciplines have recognized her work and its value to their field.

• The American Physical Society, which includes many of the world’s most prominent physicists, in March named Jayaraman as a fellow, an honor bestowed on those who have made exceptional contributions to physics. Such fellowships are awarded to fewer than 0.5% of APS’ more than 55,000 members in any given year.
• The American Chemical Society selected Jayaraman to serve as deputy editor of its new, fully open-access journal ACS Polymer Au (Gold).
• The American Institute of Chemical Engineers this summer announced that Jayaraman would receive the 2021 Impact Award, administered by its Computational Molecular Science and Engineering Forum (COMSEF), at the AIChE annual meeting in November.

Jayaraman leads a computational materials research lab as a professor of chemical and biomolecular engineering and materials science at UD. 

She also loves to teach, loves to be in front of a crowd of eager learners, and is devoted to sharing science with the broadest possible audience, making quality science communication a priority.

“I’m passionate about science, education, and training our next best scientists,” she said. “I also believe that the science we create should be shared. I share that in my classroom and with my research community through our papers. I also strongly support that dissemination with a broader community around the world. This motivated me to take on this new editorial role in the new open-access journal ACS Polymer Au.”

What drives her in all these roles is her love for polymers, substances made up of long chains of uniform molecules. They are everywhere and make amazing building blocks, whether they are produced naturally (silk, hair, DNA for example) or synthetically (plastics, for example).

“They can be in tires, in rocket ships, on a plane and they can be designed to carry a drug into the human body,” she said. “We’re all made of biopolymers, chain molecules that have a unique chemistry programmed in.”

Working at different scales requires the kind of expertise her team has.

“Polymers have non-trivial structures at different scales — Angstrom scale, nanoscale, and micron-scale,” she said. “To study these materials computationally, one has to select or develop the right model that captures that structure at the scale of interest. One model doesn’t fit all, and that adaptability is something my group works on.”

Her computational expertise pulls many aspects of scientific inquiry together, but she especially cherishes her collaborations with two kinds of researchers, she said — those who synthesize polymers and those who characterize the materials in a wet lab.

One close-to-home example is Jayaraman’s collaboration with UD’s Kristi Kiick, Blue and Gold Distinguished Professor of Materials Science and Engineering. She worked with Kiick to characterize protein-like polymers, predict their stability and thermodynamic behavior in specific conditions and ensure they will behave the way Kiick and her team want them to behave in their biomedical research.

That points the way to new materials and better materials.

Computational skills are essential to advances in research and Jayaraman’s excellence in that work is reflected in the honors received from these three independent scientific societies.

Recognizing Jayaraman’s research accomplishments, APS cited her “insightful development and use of molecular modeling, simulation and theoretical studies of structure and thermodynamics in polymer nanocomposites, conjugated polymer blends, nucleic acids and thermoresponsive peptide-polymer conjugates.”

The Impact Award from AIChE COMSEF recognizes outstanding research in computational molecular science and engineering, including methods and applications.

The editing position with ACS Polymers Au reflects her leadership in polymers research and her communication skill. She and Associate Editor Prof. Harm-Anton Klok of the Federal Institute of Technology (EPFL) in Lausanne, Switzerland, just released the first issue of the journal.

“Arthi is the complete package,” said Jan Genzer, S. Frank and Doris Culberson Distinguished Professor of Chemical and Biomolecular Engineering at North Carolina State, who nominated her for the APS fellowship and was a co-adviser for Jayaraman when she was a doctoral student at N.C. State. “She mentors her students and collaborates with a large group of people. Many of her collaborators are experimentalists and that’s very atypical for people who do simulation and modeling. She is highly sought after by my colleagues who do experiments.”

The daughter of an engineer and an educator, Jayaraman said she loved computer programming when she was growing up in Madras, India, and that lifelong skill along with her interest in chemical sciences has served her well.

“My parents were always supportive and were a driving force for me and my sister, who is an accomplished researcher in biophysics,” Jayaraman said. “I was fortunate to have that push and encouragement from my parents. We came from a lower-middle class family. My parents prioritized our education over luxury and that paid off.”

Jayaraman earned her bachelor of engineering degree in chemical engineering from the Birla Institute of Technology and Science in Pilani, India, and her doctorate in chemical and biomolecular engineering at N.C. State. She did postdoctoral research at the University of Illinois-Urbana. Before joining UD in 2014, she was an assistant professor and Patten faculty fellow at the University of Colorado at Boulder.

Her other awards include the Department of Energy (DOE) Early Career Research Award and young investigator awards from the American Institute of Chemical Engineers (AIChE) and the American Chemical Society (ACS).

The Ophiuchus star-forming complex offers an analog for the formation of the solar system, including the sources of elements found in primitive meteorites

A region of active star formation in the constellation Ophiuchus gives astronomers new insights into the conditions in which our solar system was born. In particular, a new study of the Ophiuchus star-forming complex shows how our solar system may have become enriched with short-lived radioactive elements.

Evidence of this enrichment process has been around since the 1970s when scientists studying certain mineral inclusions in meteorites concluded that they were pristine remnants of the infant solar system and contained the decay products of short-lived radionuclides. These radioactive elements could have been blown onto the nascent solar system by a nearby exploding star (a supernova) or by the strong stellar winds from a type of massive star known as a Wolf-Rayet star. 

The new study used multi-wavelength observations of the Ophiuchus star-forming region, including spectacular new infrared data, to reveal interactions between the clouds of star-forming gas and radionuclides produced in a nearby cluster of young stars. Their findings indicate that supernovas in the star cluster are the most likely source of short-lived radionuclides in the star-forming clouds.

“Our solar system was most likely formed in a giant molecular cloud together with a young stellar cluster, and one or more supernova events from some massive stars in this cluster contaminated the gas which turned into the sun and its planetary system,” said co-author Douglas N. C. Lin, professor emeritus of astronomy and astrophysics at UC Santa Cruz. “Although this scenario has been suggested in the past, the strength of this paper is to use multi-wavelength observations and a sophisticated statistical analysis to deduce a quantitative measurement of the model’s likelihood.”

First author John Forbes at the Flatiron Institute’s Center for Computational Astrophysics said data from space-based gamma-ray telescopes enable the detection of gamma rays emitted by the short-lived radionuclide aluminum-26. “These are challenging observations. We can only convincingly detect it in two star-forming regions, and the best data are from the Ophiuchus complex,” he said.

The Ophiuchus cloud complex contains many dense protostellar cores in various stages of star formation and protoplanetary disk development, representing the earliest stages in the formation of a planetary system. By combining imaging data in wavelengths ranging from millimeters to gamma rays, the researchers were able to visualize a flow of aluminum-26 from the nearby star cluster toward the Ophiuchus star-forming region. 

“The enrichment process we’re seeing in Ophiuchus is consistent with what happened during the formation of the solar system 5 billion years ago,” Forbes said. “Once we saw this nice example of how the process might happen, we set about trying to model the nearby star cluster that produced the radionuclides we see today in gamma rays.”

Forbes developed a model that accounts for every massive star that could have existed in this region, including its mass, age, and probability of exploding as a supernova, and incorporates the potential yields of aluminum-26 from stellar winds and supernovas. The model enabled him to determine the probabilities of different scenarios for the production of the aluminum-26 observed today.

“We now have enough information to say that there is a 59 percent chance it is due to supernovas and a 68 percent chance that it’s from multiple sources and not just one supernova,” Forbes said.

Lin noted that this type of statistical analysis assigns probabilities to scenarios that astronomers have been debating for the past 50 years. “This is the new direction for astronomy, to quantify the likelihood,” he said.

The new findings also show that the number of short-lived radionuclides incorporated into newly forming star systems can vary widely. “Many new star systems will be born with aluminum-26 abundances in line with our solar system, but the variation is huge—several orders of magnitude,” Forbes said. “This matters for the early evolution of planetary systems since aluminum-26 is the main early heating source. More aluminum-26 probably means drier planets.”

The infrared data, which enabled the team to peer through dusty clouds into the heart of the star-forming complex, was obtained by coauthor João Alves at the University of Vienna as part of the European Southern Observatory’s VISION survey of nearby stellar nurseries using the VISTA telescope in Chile.

“There is nothing special about Ophiuchus as a star formation region,” Alves said. “It is just a typical configuration of gas and young massive stars, so our results should be representative of the enrichment of short-lived radioactive elements in star and planet formation across the Milky Way.”

The team also used data from the European Space Agency’s (ESA) Herschel Space Observatory, the ESA’s Planck satellite, and NASA’s Compton Gamma Ray Observatory.