Ashley Hastings (Hixon Group)

Leveraging Nitrogen-Linkages in the Formation of a Porous Thorium-Organic Nanotube

April 21, 2021

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Ashley Hastings is a third-year graduate student advised by Prof. Amy Hixon, associate professor in the Department of Civil and Environmental Engineering and Earth Sciences. Hastings presented her research titled, “Leveraging Nitrogen-Linkages in the Formation of a Porous Thorium-Organic Nanotube" during the ND Energy PD&GS Seminar in April 2021.

Hastings’ research is focused on the actinide elements, which bear great importance for the interests of nuclear power production and security. The actinide series is comprised of the chemical elements with atomic numbers 89 to 103 (actinium through lawrencium).

“These elements are still relatively new compared to the rest of the periodic table, and there are gaps in our fundamental knowledge of them,” Hastings said.

To fill these gaps, Hastings makes new actinide-based materials and studies their properties. She synthesizes porous materials known as metal-organic frameworks (MOFs). MOFs are useful for many practical applications in nuclear energy, such as waste separation and storage, due to their high stability and surface areas.

“As the actinide elements are radioactive, we are definitely interested in exploring stable chemical forms,” Hastings said. “Actinide-based MOFs meet this need as well as a platform for sequestering other toxic species like fission products or volatile iodine.”

As part of the National Nuclear Security Administration (NNSA)-funded Actinide Center of Excellence (ACE), Hastings’ research benefits from extensive collaboration. She works with MOF experts at Northwestern University and computational chemists at the University of Minnesota.

While the labs within ACE are home to many of the analytical techniques she needs to conduct her research, Hastings also utilizes ND Energy’s Materials Characterization Facility (MCF) for other capabilities. She has been trained on powder X-ray diffraction (PXRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis coupled with mass spectrometry (TGA-MS).

“Ian Lightcap and Anna Matzner have been integral in my instrument training and incredibly available for research support,” Hastings said of the staff at the MCF.

Hastings earned her bachelor’s degree in chemistry at the University of Mary Hardin-Baylor in Belton, Texas. Prior to her senior year, she participated in a nuclear and radiochemistry summer school at Brookhaven National Laboratory. There she was introduced to the field and made a connection that would ultimately result in her working in the Hixon group. By the time she visited Notre Dame as a prospective student, it was her top choice for graduate school.

“I was immediately attracted to the research as well as the group dynamic. We are quite cooperative and there are many avenues for support,” Hastings said. “As a graduate student now, I can see how these qualities are incredibly beneficial.”

Throughout the pandemic, Hastings has felt supported by the University with job security, access to testing and vaccination, and protective measures that ensure safe in-person research.

“I took the opportunity to prepare for my oral candidacy exam when we had to work from home, but thankfully we were some of the first to return to in-person research,” she said.

Through her research, Hastings has learned that it is important to be transparent about the scientific process. While researchers often consult the literature to plan their experiments, it’s critical to understand those are merely the successes. For Hastings, earning a Ph.D. is about building on a foundation of failed experiments to find what ultimately works.

“This can be discouraging as a graduate student navigating their individual research,” Hastings said. “My hope is that we can work to be more candid about the experimental progression that results in interesting stories and solutions to research problems.”

You can learn more about Hastings and her research here.