Meet Sergei Lymar

Chemist Sergei Lymar wasn’t too surprised last year when his daughter Dasha, then a graduate student at the Massachusetts Institute of Technology, called to tell him that her inorganic chemistry textbook made reference to his work on reactive nitrogen oxides. Lymar has made a career of studying the small inorganic nitrogen-oxygen compounds that are involved in everything from human health to radioactive waste management.

Sergei Lymar

For the past decade, Lymar has been using electron accelerators at the Brookhaven Chemistry Department’s Center for Radiation Chemistry Research (CRCR) to generate reactive nitrogen oxides and observe their reactions.

“These reactions are important in biology where they can be both harmful, contributing to a number of diseases, and beneficial, participating in combating microbial infection,” Lymar said.

The reactive nitrogen oxides are also central in environmental chemistry and in the chemistry occurring within nuclear waste storage tanks. Soon after coming to Brookhaven in 1997, Lymar won a six-year grant from the Department of Energy’s Environmental Management Science Program to study the implications of inorganic nitrogen chemistry for waste management and remediation.

“The molecules we are studying contain less than half a dozen atoms – only nitrogen, oxygen, and hydrogen --but there is little that’s simple about their chemistry,” Lymar said. “For one thing, these species often have only a fleeting existence, reacting in microseconds, so we must generate them faster than that to actually observe them.”

This is best done with the pulse radiolysis technique available at Brookhaven’s CRCR, where researchers pass short bunches of electrons from an accelerator through sample solutions. In its wake, each electron leaves thousands of broken water molecules and these extremely reactive fragments are used for making the nitrogen oxide species. Brookhaven is one of only three U.S. facilities where the pulse radiolysis technique is available.

“In the waste management project, we were mainly concerned with the radiation-induced accumulation and reactivity of a particular, high-energy nitrogen oxide that can present a safety concern,” Lymar said. “We also have explored the application of the strong oxidizing power of this species in waste remediation technologies. This information is essential for making more informed decisions concerning the waste disposal options.”

Part of DOE’s Hydrogen Fuel Initiative relates to the conversion of solar energy by splitting water into hydrogen and oxygen. Lymar is also involved in the application of radiation chemistry techniques to this project.

Born in the Ukraine, Lymar received his B.S. and M.S. degrees from the Moscow Institute of Physics and Technology, and his Ph.D. from the Institute of Catalysis of the Russian Academy of Sciences in Novosibirsk. He worked as a senior research associate at the Institute of Catalysis before joining the Oregon Graduate Institute of Science and Technology as a visiting scientist in 1991.

Lymar’s wife Elena is an assistant biochemist at Brookhaven, working on the application of gold nanoparticles for labeling proteins and protein complexes. Their busy lives allow little time for leisure activities, but Lymar, a paramilitary-trained scuba diver, enjoys diving and windsurfing in the Caribbean when he can manage a vacation.