by Erica Andersen
When University of Pennsylvania undergraduate Kyle Kersey wants to describe his research, he finds it difficult to delve into the intricacies of coordination, solubility and steric effects. So he’s settled on a different tactic.
"The word I like to use is ’humbling,’" says Kersey.
In the lab, he works to synthesize new radioactive compounds, and the reactions don’t always proceed as planned. In fact, they rarely ever do.
"It’s never going to work the first time. You should be concerned if it does," he says, "because then you have to figure out how to do it again. I feel like I’ve done it the same way 10,000 times and it never gives me the same result twice."
Kersey is a junior in Penn’s Vagelos Integrated Program in Energy Research, or VIPER , studying chemical and biomolecular engineering in the School of Engineering and Applied Science and chemistry in the School of Arts & Sciences. He conducts research with uranium and thorium in the lab of Eric Schelter , an associate professor in the Department of Chemistry.
Even though uranium was discovered centuries ago , scientists still don’t understand much about its highest oxidation state, uranium(VI), in which each atom is missing six electrons. Kersey is trying to create a compound with a double bond between uranium(VI) and carbon, which hasn’t been done before. It’s a challenging synthetic problem.
"Uranium tends to prefer really hard donors like nitrogen and oxygen," Kersey says, referring to elements that easily lend their negatively-charged electrons to the positively-charged uranium.
Carbon, in comparison, is a soft donor. It’s not as generous with its electrons, so it’s difficult for carbon to form a stable bond with uranium. For Kersey, that means trying many different ways of coercing the molecules into forming the product he wants.
"So much of it is trial and error," Kersey says.
Eventually, his work could help improve the storage of spent nuclear fuel. In nuclear reactors, uranium(VI) bonds with two oxygen atoms to form uranyl, a byproduct of energy generation.
"The problem is that uranyl is very water soluble," says Kersey. "When we store nuclear waste in cladding and bury it deep underground, the cladding can crack under various weather conditions."
As uranyl is both toxic and radioactive, this poses an issue for its long-term storage.
"It leaches into the groundwater and you have radioactive contamination," Kersey says.
Learning more about the chemistry of uranium(VI) could help scientists tailor the reaction to form a byproduct that’s not as water soluble and therefore poses less of a threat to the environment.
But for Kersey, the real draw is finding the right combination of reagents, solvents and techniques to create his desired product.
"This specific compound is novel," he says. "It’s a new, challenging synthetic build. That’s really interesting."
Kersey is no stranger to the lab bench. He’s also working on two other synthesis projects in Schelter’s lab, both involving thorium. And thanks to Michio Kaku , a well-known futurist and theoretical physicist, he worked on three different projects in two separate labs before even coming to Penn.
The two met at an interview and dinner event honoring Kaku in Louisville, where Kersey grew up. He was a freshman in high school at the time.
They were talking for a little bit, Kersey says, when Kaku asked if his high school offered any mentoring partnerships with the University of Louisville for students interested in research. Kersey didn’t think so, but he was intrigued by the possibility of working in a lab before college. Luckily, the dean of Louisville’s Speed School of Engineering also happened to be at the event, and Kersey approached him with the idea.
"So that’s how I got started in the physics department doing optics work," Kersey says. "I stayed there for about two years until my interests started to shift more toward chemistry and chemical engineering."
In the Schelter lab at Penn, Kersey works with depleted uranium. It’s not as potent as natural or enriched uranium, but it still requires some precautions. His workstation, known as a glove box, is an enclosed cabinet with a thick window. Two large black rubber gloves integrated into the window allow him to carry out his experiments. Since thickly gloved hands don’t allow for much precision, he first had to learn to use a pair of long tweezers to grasp small glass vials and thin pipettes.
It took him several weeks to figure out a technique that worked, which was made more difficult by the fact that glove boxes are designed for right-handed people, and he’s left-handed. Now, he can move materials deftly around the box and carry out his experiments with ease.
Following his graduation from Penn, Kersey hopes to pursue a Ph.D. in nuclear science and engineering.
"I’ve always been really fascinated with nuclear energy," he says. "It is amazing to be able to take this mineral from the earth and create so much energy out of it."
Kersey credits the VIPER intensive summer research experience with accelerating both his lab skills and chemical understanding.
He describes developing a "physical intuition," and explains that he can now figure out which chemicals to use even if he doesn’t know the more complex details of their interactions.
"When you get the trial by fire over the summer, it helps," Kersey says. "You form a sense of comfort that you wouldn’t necessarily expect to have in my case, as a junior with two semesters of organic chemistry and that’s it."
After two summers, a spring semester and countless hours in the lab, he looks forward to his fourth and final VIPER research experience next year. He ultimately hopes to publish his work, but that’s not what keeps him coming back to the lab every day. Instead, he’s driven by the synthetic challenge and the opportunity to advance scientific knowledge.
"You will have an impact regardless of the end result," he says. "You have done the work and you’ve contributed something to field. That’s a good feeling."
One in a series of features on students enrolled in the Vagelos Integrated Program in Energy Research at Penn.