‘Playing’ with fire

What’s in a flame? That basic question has driven Richard L. Axelbaum, Ph.D., associate professor of mechanical engineering, for more than 20 years in his career as teacher and researcher in combustion, materials and environmental sciences.

Thanks to his pursuit of understanding the phenomena of fire and light, Axelbaum and colleagues have discovered a wealth of new materials and come up with a highly regarded patented technique to produce valuable particles in the nanometer-sized range.

Fire and light also have been the driving force behind Axelbaum developing a theory that would enable the elimination of soot, the most troublesome of all air pollutants, in the flame and combustion environment.

For more than a decade, Axelbaum has conducted innovative research in synthesizing nanometer-sized particles — nanoparticles, as they are called in the burgeoning field of nanotechnology. These particles — just 10 to 100 atoms across — are the building blocks for nanostructured materials; when they are formed into final parts, their properties are far superior to those made from conventional materials.

Nanostructured materials can be used for a variety of industrial uses, most notably in the electronics, aerospace, defense, medical and sports and recreation industries.

Axelbaum has developed a patented process that makes nanoparticles smaller and more pure than competing technologies, and the process is faster and cheaper than existing commercial processes for conventional materials. He calls his technology the sodium/halide flame and encapsulation technology (SFE).

With an intense, turbulent flame inside a flow reactor, Axelbaum uses sodium reduction of metal halides, such as boron trichloride and titanium tetrachloride, to produce metal and ceramic nanoparticles.

While flames are used to produce hundreds of millions of tons of materials annually from silica for fiber optics to carbon black for tires, Axelbaum is the first person to patent a flame technique that makes stable nonoxide materials in the nanoparticle range. The SFE technology is licensed to AP Materials Inc., St. Louis.

His group has produced six metals and four ceramics with the technique, and he estimates that more than 30 metals, intermetallics, ceramics and composites can be produced with his technology.

“Material production is accomplished in a single step with our technology,” Axelbaum said. “The key feature of the process is that we’re able to produce stable, high-purity particles in large quantities. We’re also able to have control of particle size and shape. Our present focus is tantalum metal for electronic capacitors. The nanopowders will allow for smaller, faster and more sophisticated electronics.”

Axelbaum grew up with his three brothers in University City and Creve Coeur, Mo., graduating from Parkway Central High School in 1973 and enrolling at Washington University that fall.

“I’d always been good in math and science and I loved building things,” said Axelbaum, whose father was an industrial engineer and a graduate of WUSTL.

After graduating from the University, he worked a year with General Electric and then three more with Barry Wehmiller in St. Louis, before being accepted for graduate work at the University of California, Davis. There he first probed interests in optics and combustion-generated soot, studying with physicist Thomas Cahill, Ph.D., a renowned air quality researcher.

“Over time, I realized what I really wanted to do was apply optics to study the thermal sciences,” Axelbaum recalled from his second-floor office in Jolley Hall. “Then a world-renowned mechanical engineer named Ed (C.K.) Law came to campus. His expertise provided me the perfect fit of optics, thermal science and combustion.”

At UC-Davis, a unique gathering of office mates catalyzed a spiritual awakening in Axelbaum that led to his embracing Orthodox Judaism, the focus of his life to this day. In his office were an atheist, a born-again Christian, a devout Muslim, and Axelbaum, then a non-practicing Jew.

“We had lively discussions and when a question would be posed about the stand that Judaism took on certain issues, I’d respond, ‘I don’t know, but I’ll find out,'” Axelbaum said.

“As I did this, I learned about my religion, began to appreciate its beauty and got more involved.”

Axelbaum said Orthodox Judaism gave him definitive answers based on traditions more than 3,500 years old. He likes the discipline and camaraderie that thrice-daily services at his synagogue, Young Israel in University City, provides. His family, wife Maurie, sons Aaron, 16, and Ari, 14, and daughter Adira, 11 — who attend Orthodox Jewish Day School — are equally committed.

He is the immediate past-president of his synagogue and was responsible for designing an optical device for his synagogue that is now used across the nation. He received the Innovation of the Year Award from the National Council of Young Israel for this invention.

Axelbaum sees no conflict between science and religion.

“Science is evolving all the time,” he said. “It has evolved into a position today much more compatible with religion than it was 100 years ago. For instance, instead of a steady state view of the universe totally inconsistent with the creation scenario, science now recognizes that there was a beginning to the universe. The fact that science can make such a radical change to conform with religion shows that science and religion don’t have to be at odds.

“Religion also gives added meaning to my occupation. The Torah, the Jewish Bible, teaches that fire was a gift to mankind from the Creator. Anyone that has delved into the mysteries of fire and sees how closely it is tied into the existence of man has to realize that the creation of fire is no accident.”

Using his imagination and knowledge of combustion, Axelbaum in the late ’90s created something that defies imagination: a spherical flame, a veritable “ring of fire.” Funded by NASA, Axelbaum set out to prove his flame design theory, which holds, in part, that industrial flames can be designed to be soot-free. He used the microgravity environment to develop a spherical flame — in the absence of gravity, the flame is no longer buoyant, which means it does not rise and thus can be made spherical.

He employed drop tower studies — dropping an experiment in a tower for two-to-five seconds creates the equivalent of microgravity in space — to observe the phenomenon and concluded that he can make flames that are extremely strong and are free of soot.

“Rich is a marvelous professor and a great citizen,” said David A. Peters, Ph.D., professor and chair of mechanical engineering. “I have known him since 1975 when he was a student in one of my classes. We all knew then that he was destined for greatness. His research has always been in the area of combustion, but he has been very innovative in combining that with materials science.

“Rich is one of our most popular teachers, and is central in our courses on thermodynamics, combustion, and heat transfer. He is great at combining practical and theoretical knowledge into a coherent class structure.”

Axelbaum also has played a vital role in reestablishing the Environmental Engineering Science program. He credits his colleagues, particularly Pratim Biswas, program chair, with much of the success, but is proud to be part of this team.

In the early ’90s, Axelbaum was part of an interdisciplinary Washington University team comprising chemist William Buhro, Ph.D., physicist Kenneth Kelton, Ph.D., and mechanical engineer Shankar Sastry, Ph.D., to study nanoparticles. They were in the vanguard of the emerging nanotechnology field, sponsored by a new initiative by the National Science Foundation, and were the first to make the world’s smallest, cleanest ceramic titanium boride.

Today the core of that group is still active as members of the University’s Center for Materials Innovation (CMI), launched in the fall of 2003.

Axelbaum noted that the rabbinical writings teach that the Third Temple of the Jews will be rebuilt from fire. What exactly this means is unknown, but by combining his use of fire to create advanced materials, and his observance of Torah law, he hopes to play a very small part — a nano-part? — in that historic event.