WashU engineers to study nanoparticles’ behavior in low-temperature plasma

Products from artificial joints to semiconductor circuits to plastic bags are made using the fourth state of matter, or plasma, which is an ionized gas. Plasma changes properties depending on its temperature, and when the temperature is low, the substance is strongly nonequilibrium, meaning it changes over time.

Elijah Thimsen

Elijah Thimsen, principal investigator of the Interface Research Group at Washington University in St. Louis, will study the behavior of nanoparticles in low-temperature plasmas that may lead to the production of novel materials and novel states of matter.

Thimsen, assistant professor of energy, environmental & chemical engineering in the School of Engineering & Applied Science, received a three-year, $248,984 grant from the National Science Foundation to study the vaporization of nanoparticles in low-temperature plasmas. He will explore a new aerosol mechanism in these plasmas that has not been previously studied. The mechanism allows for materials, such as metals, to vaporize at room temperature, due to the nonequilibrium environment within the plasma.

“In addition to this being fundamentally interesting, this mechanism allows monodispersed nanoparticles to be produced that are made of materials for which production methods are unknown,” Thimsen said. “With the theoretical limits still unknown for processing material into new configurations via interactions with low-temperature plasmas, there also is a chance for experimental discovery of novel processes to alter materials in unexpected ways.”

Thimsen said preliminary evidence supports the new mechanism, which would be applicable to many different materials.

“The goal of the project is to generalize the mechanism and to use it to synthesize materials that are desired by the nanomaterials community, but have nevertheless remained elusive,” he said.

The McKelvey School of Engineering at Washington University in St. Louis promotes independent inquiry and education with an emphasis on scientific excellence, innovation and collaboration without boundaries. McKelvey Engineering has top-ranked research and graduate programs across departments, particularly in biomedical engineering, environmental engineering and computing, and has one of the most selective undergraduate programs in the country. With 140 full-time faculty, 1,387 undergraduate students, 1,448 graduate students and 21,000 living alumni, we are working to solve some of society’s greatest challenges; to prepare students to become leaders and innovate throughout their careers; and to be a catalyst of economic development for the St. Louis region and beyond.