Scented bowl: Powdered silicon can neutralise bad odour

For four years, inventing a new toilet bowl freshener has been a sideline pursuit for Michael Lefenfeld, a 25-year-old graduate student in molecular electronics at the Columbia University. Lefenfeld’s doctoral research focuses on the structure of molecules in nanoscale devices like transistors.

But his quest for a new freshener ? a search inspired by his grandfather’s wish for a quick way to neutralise smelly toilets ? led to a surprising discovery, a way to encase sodium and other explosive alkaline metals in a powdered form of silicon gel, making them much safer to handle. The powdery materials, researchers say, could eventually help pharmaceutical manufacturers sharply cut the cost of producing antibiotics and other types of drugs. In a different form, they might provide hydrogen for fuel cells in portable electronics. And lab tests suggest that the materials could be useful in environmental monitoring or in jobs like removing sulfur from petroleum.

“This could be of great, great interest for the pharmaceutical and chemical industries,” said Boris Gorin, manager of research and development at Alphora Research, a Toronto-based designer of chemical production processes that is testing the materials. “Many reactions that are easy to do in the lab with alkaline metals can’t be transferred into large-scale production today because of safety issues,” he said.

Lefenfeld’s story highlights the potential usefulness of mundane materials to nanotechnology, in which businesses are racing to create products and manufacturing processes by manipulating materials in such tiny dimensions that they are measured in nanometers, or billionths of a meter.

The field has mostly focused on the properties of recently discovered molecules like the tiny cylindrical carbon rods known as nanotubes or the light-emitting bits of silicon called quantum dots. But Lefenfeld’s work shows that breakthroughs may also come from tinkering at the molecular level with familiar materials like alkaline metals that had been written off by most researchers and executives as unlikely to produce any valuable surprises.

Industrial companies have been working with alkaline metals for 100 years, according to Owen Mathre, a retired DuPont executive who still consults for the company.

Lefenfeld splits his time between his graduate work and his job as president and chief scientific officer of SiGNa Chemistry, which he started in his parents’ apartment in New York City. The company has no employees. But Sigma-Aldrich, a leading distributor of chemicals for research, says that Lefenfeld’s powder is one of the stars among the 2,000 new chemicals in its portfolio.

So far, SiGNa Chemistry is limited to producing small quantities of the material at a Michigan State University laboratory. James L. Dye, who was hired by Lefenfeld in 2003 to help him work on the toilet bowl freshener, supervises the production.

DuPont, which has supplied sodium for the research, says it is not yet clear how much potential customers will be willing to pay for such gel-encased materials. Nor is it known whether DuPont or anyone else can profitably produce them, said Larry Fetzer, technical service consultant for DuPont’s reactive metals group. Lefenfeld said that he had been talking to venture capitalists, but that he was in no rush to expand SiGNa, named for the symbols for silicon and sodium with a ‘g’ for gel.

Lefenfeld’s freshener quest began four years ago. His grandfather Murray Katz, a retired beer and soda distributor, longed for the equivalent of breath mints to toss into smelly toilets. “Mickey,” he said, “you should invent it.”

Lefenfeld was an avid science student in high school, and as a college student at Washington University in St Louis, he said, he expected to forge a career in research on diabetes, which he has had since he was 8.

But he became intrigued with materials science while taking a course on micro-encapsulation from Dr Curt Thies, and spent the next summer working at Thies Technology, a company Thies had founded to commercialize his research.

After graduating from college in 2002, Lefenfeld went on to do research at Bell Laboratories and DuPont on electronics built from flexible plastics. By the time he left DuPont for graduate school, he suspected that his after-hours work on Plop and Drop, as they called his grandfather’s concept, had broader uses than they imagined.

NYTNS