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International Symposium Honors Somasundaran

Birthday presents come in all shapes and sizes, but Prof. Ponisseril Somasundaran's recent birthday present was unique: a Symposium on Surfactants and Polymers at Interfaces. Dr. Somasundaran, La von Duddleson Krumb Professor of Mineral Engineering, was honored by the NSF Engineering Research Center for Particle Science and Technology and the University of Florida Center for Surface Science and Engineering for his invaluable contributions to surfactant and polymer science and technology. The symposium, part of an international conference, was an appropriate choice of gifts since Prof. Somasundaran is internationally recognized as an authority in his field.

After decades of research, Prof. Somasundaran still exhibits the enthusiasm of a child receiving a new toy when he talks about his area of expertise, its many applications and the potential for important discoveries. Surfactants are surface-active compounds that have industrial applications for such varied uses as coatings, dispersions, image display, nanoelectronics, personal care products, soil decontamination, waste treatment and corrosion prevention. New tools, such as the atomic force microscope, have allowed greater understanding of reactions at the atomic level.

"We found that particles that have tethers (hairs) that are individually charged plus and minus will be attracted to a surface with a similar charge whereas particles of the same net negative charge will not deposit on a negative surface. This happens, I proposed, because friendly tethers can reach out to the surface to hook up whereas the antagonistic ones will retract away from the surface. It is the dynamics of these tethers that are most important and exciting."

This is important in processes that require one substance to bond with another even under hostile conditions. "For example, in titanium implants that replace teeth, we want tissue to grow, not microbes. We need to find the right protein that will make tissue cells, not bacteria, adhere to the titanium," he said.

One important advance made by Prof. Somasundaran has been the development of sugar-based detergents that dissolve grease and are milder than soaps, tolerant of hard water, easily digested by microbes and leave no trace in the environment. In addition to his research in biodegradable surfactants, he notes the broader environmental uses where surfactants are essential. They are used to remove sulfur from coal before it is burned, thus reducing acid rain, and are likely to provide a method to eliminate arsenic in groundwater that puts at risk as many as 70 million people in Bangladesh alone.

Arsenic poisoning is of growing concern in the United States, where landfills containing pesticides leach arsenic into the ground water, e.g., in some areas of Maine and New Jersey. "The arsenic problem created by gallium arsenide in semiconductor chips is just around the corner as more and more chip-containing gadgets are being discarded," said Prof. Somasundaran, who is known as "Som."

"And then there are thousands of acres of lakes of phosphate puddings in Florida, the ones you don't see from Disney World," he said, describing phosphate slimes that take 20 or 30 years to settle for any land reclamation.

While there will always be unsolved problems, many practical solutions have been found, thanks to the industry-university connection. Working with industry is not new to Prof. Somasundaran. As early as the 1970s, during the oil crisis, he brought together major U.S. oil companies to discuss surfactants for releasing oil trapped in the pores of rock. The process, known as micellar flooding, results in millions of barrels of previously unrecoverable oil. Surfactants added to water forced through the rock break down surface tension between the oil and water, allowing both to flow through the pores of the rock and be recovered. An analogous process can be used to recover trace metals by crushing rock, adding a surfactant and then bubbling air into the mixture. The surfactant coats the mineral particles containing metal and allows air bubbles to attach to it, floating the miniscule metal particles to the surface for recovery.

A member of the National Academy of Engineering since 1985, "Som" has been elected to the Chinese Academy of Engineering, Indian National Academy of Engineering and Russian Academy of Natural Sciences, among others. He cherishes the most his Ellis Island Medal of Honor for Distinguished Americans, conferred in 1990. Despite his own collection of awards and accolades, he is most proud of his father's "Thamra Patra" medal recognizing his part in the march of the "salt movement" of Mahatma Gandhi for Indian independence.

A dynamo of energy, Prof. Somasundaran took on an additional role three years ago as director of the NSF Industry/University Cooperative Research Center, which is supported by the National Science Foundation, Department of Energy and 14 companies. In that role, and as director of the Langmuir Center for Colloids and Interfaces, he works with an interdisciplinary faculty, including Paul Duby of the School of Mines, Carl Gryte and Alan West of Chemical Engineering and Applied Chemistry and Nicholas Turro of the Departments of Chemistry and Chemical Engineering and Applied Chemistry.

He rattles off the most recent initiatives-smart microgels to deliver drugs, electrochemical methods of investigating corrosion inhibitors and a revolutionary way to provide a vehicle for gene therapy using the interaction of viruses with particles with positive and negative hairs. For "Som," work is never done.

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