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ORNL Postdoc Research Profile: Lymarie Semidey-Flecha

Measuring the tiny world of nanoscience


Dr. Lymarie Semidey-Flecha

A postdoctoral research fellow at Oak Ridge National Laboratory, Lymarie Semidey-Flecha accesses ORNL’s supercomputer to test theories on the size characteristics of nanocatalysts, which could assist scientists in developing nanotechnology.

If you wear weather-resistant clothing or the latest brand of sunscreen, you probably have nanotechnology to thank for it. This relatively new scientific field is taking off quickly; and while there are still many unknowns, the potential for technological advancement is obvious.

Nanotechnology is the science of the very small—a nanometer is only one-billionth of a meter. Yet nano-sized materials have many advantages, often possessing unique properties that can lead to chemical reactions used to create a variety of useful chemicals and, even, new fuels. Such nanocatalysts are a cutting edge technology, according to Dr. Lymarie Semidey-Flecha.

Puerto Rican native Semidey-Flecha received her doctorate in chemical engineering from the Georgia Institute of Technology in 2009. A year later, she is one of many fellows with the Postdoctoral Research Associate Program at Oak Ridge National Laboratory—a one-year program that is renewable for up to three additional years—administered by the Oak Ridge Institute for Science Education, which gives young scientists the opportunity to expand their research interests and gain world-class experience.”

While nanocatalysts offer exciting opportunities, they are often difficult to produce and their properties are difficult to predict. Through her research at the Center for Nanophase Materials Sciences, Semidey-Flecha works under the supervision of ORNL’s Dr. Ye Xu, an expert in computational catalysis—a field in which chemistry-based computational methods are used to understand and explain experimental observations.

Semidey-Flecha is working with graphene, a carbon sheet that is only one atom thick and has a great ability to conduct electrons. More specifically, she is attempting to determine the properties of tiny metal particles that can be grown on graphene atop metal surfaces. In recent years, graphene on metal surfaces has shown promising as a template for metal nanocluster formation, allowing the properties of the graphene to be altered.

These metal nanoclusters and their potential uses are of great interest to the nanoscience community, but there is still much that remains unknown.

“Our goal is to help our experimental collaborators by guiding them towards what materials are best suited for the formation of the nanocatalyst of their interest,” Semidey-Flecha said.

This is often accomplished using ORNL’s supercomputer Jaguar. The computer calculates simulated concepts of the materials Semidey-Flecha is interested in testing, which she later evaluates and reports.

Luckily, she enjoys working with computers and often feels more like a computer scientist than a chemical engineer, having learned a series of computer languages and operating systems during her studies.

“To be honest, I sort of fell into scientific research,” Semidey-Flecha recalled. “But when I realized that, even as a chemical engineer, I could still base my research on computational work or biological studies, I fell in love with the idea of research”.

“With the work I am doing here at ORNL, I am expanding my doctoral knowledge beyond my thesis and learning how to apply that knowledge to other applications of material science,” she said.

Semidey-Flecha is not yet certain of her future research endeavors but is interested in the search for improved energy resources and the use of nanocatalysts in pharmaceutical applications. Whatever she chooses to pursue, she will continue exploring novel ways to use her chemical engineering degree.