Christine Duval investigating novel methods for separating elements for wind turbines, electric vehicles, smart phones, nuclear power
Case Western Reserve University scientist Christine Duval will investigate novel and more environmentally safe methods to separate so-called "rare- earth elements" used for wind turbines, electric vehicles and smart phones.
Duval, an assistant professor of chemical engineering in the Case School of Engineering, was awarded a five-year, $549,000 National Science Foundation (NSF) Faculty Early Career Development Program (CAREER) grant to pursue the research.
She will investigate specialty polymer coatings applied in many industries, including to separate rare-earth elements from industrial waste or mined sources. Current extraction methods-more than a half-century old-produce large physical and carbon footprints, and radioactive waste, Duval said.
If successful, these new specialty coatings could be applied to membrane filters or placed in electrochemical devices to separate the desired rare-earth elements from undesired radioactive materials-and without negative consequences.
The CAREER award is considered the foundation's most significant grant for junior faculty members whom NSF believes "have the potential to serve as academic role models in research and education and to lead advances in the mission of their department or organization."
"I'm so excited about this approach and I've been wanting to do this research for a long time," she said. "Our preliminary data already shows some possible success, and that our molecular-level design choices can make a difference."
Venkataramanan "Ragu" Balakrishnan, the Charles H. Phipps Dean of the Case School of Engineering, lauded Duval for her "unique expertise in radiochemistry" and said the school was "honored that her incredible talent is gaining recognition at this level."
"Dr. Duval finds new and better ways to develop and use nuclear materials for a variety of applications including electricity generation, clean energy, and even treatments for cancer," Dean Balakrishnan said. "(She) works to lessen the environmental impact of developing these materials and has created a research enterprise intentionally designed to improve diversity and broaden impact in the field."
Ongoing and expanded research
Duval will focus on separating what are known as "f-elements" (lanthanides and actinides)-among the heaviest found in nature. Both play a crucial role in applications of nuclear technology, including electricity generation, clean energy technologies and cancer treatment, she said.
Lanthanides and actinides are harvested from natural resources through traditional mining approaches or by processing industrial waste sources and chemically separated.
"These polymer coatings can enable alternative separation technologies to solvent extraction that have smaller physical footprints and minimize the volume of waste generated," Duval said. "Usually, we try to separate elements by their molecular size or electrical charge, but some lanthanides and actinides are practically the same in both, so we have to find new ways."
One of those new ways, Duval said, is by leveraging the "hydrophobicity" of the coatings, meaning how much the coating surface doesn't like water.
"We're learning that this can play a role in the separation," she said. "That's one area that is showing some promise and one that was pretty surprising."
Duval has already conducted similar research-work involving new separation methods and materials, but from different sources.
In 2021, Duval was named lead researcher on a four-year, $1.7 million NSF grant to develop a new way to recover four valuable rare earth elements from phosphogypsum, a mining waste mixed with radioactively contaminated water. On that project, she's working with Julie Renner, an assistant professor of chemical and biomolecular engineering at Case Western Reserve, and other scientists from Clemson and Penn State universities.
In June 2020, Duval was awarded a five-year, $750,000 U.S. Department of Energy Early Career Research Award to work on radiochemical separations for nuclear medicine and cancer treatment.
The importance of rare-earth metals
The research comes amid a global competition to produce greater amounts of rare-earth metals.
Nearly all critical rare-earth metals are imported by the United States, according to the U.S. Geological Survey, leading to a push to produce them domestically.
In February 2021, President Joe Biden signed an executive order authorizing the defense department to investigate U.S. reliance on foreign imports and a lack of domestic processing of rare-earth elements, which are mainly processed in China.
The metals are common in nature, but dispersed in smaller concentrations, harder to mine and not easily extracted from their surrounding elements-several of which are radioactive.
