Symposium Showcases Graduate Talent

Two years ago, graduate student Claudia Schultze and her adviser, Professor Marc Donohue, developed an idea to foster industry/academic relations that has quickly become a tradition in the chemical engineering department. Each September, graduate students organize a symposium that highlights their research at the master's and doctoral candidate levels. The event brings faculty, graduate students, and industry together to discuss the Department's innovative and challenging research projects and their application and utility within industry.

In 1996, the symposium's success can be attributed to the generosity of DuPont Education Foundation; Exxon Company, U.S.A.; and the W.R. Grace Foundation, through the Grace Davison Division. Collectively, they underwrote a significant portion of the symposium's costs and the efforts of Schultze and graduate students Katrin Parsiegla and Markus Rudek. The trio worked for several months to create brochures and coordinate presentations for the two-day event. Highlights included a reception for industry representatives at Baltimore's Inner Harbor; a keynote address by Michael King, senior vice president of science and technology at Merck & Co., Inc.; and the poster session featuring 16 different research areas. Guests from industry voted on the top three posters. Symposium attendees walked away with a better understanding of the many types of research by graduate students and their advisers. The guests also received a book containing presentation abstracts and resumes of the graduate students. "The first year, we had 12 industry representatives attend," Schultze recalls. "In 1996, we made a concentrated effort to make the symposium more professional, which resulted in a threefold increase in representatives. The symposium is equally a student event; we invite first-year graduate students to give them the opportunity to meet other students and faculty."

If Schultze wasn't already busy enough working on her doctoral thesis (she's targeting May 1998 as her graduation date) and planning the symposium, she finds time to train and race competitively in triathlons.

The Science of Mixing

Everyone knows that oil and water don't mix. No one knows it like Associate Professor Kate Stebe, who studies the dynamics of what's going on in the interface between two substances. The interface is the molecular layer where one liquid or gas meets another mixture.

Whether it's liquid-liquid, gas-gas, or gas-liquid mixtures, Stebe studies how long it takes for molecules to reach equilibrium at the interfaces, the changes in behavior that occur at interfaces, and how it might be possible to control those characteristics. In particular, Stebe investigates the role of surfactants at interfaces. Surfactants, or surface active molecules, are "schizostructures," according to Stebe. "There is one part of the molecule that likes to be in water, and another that does not," she explains. When combined with another solution, such as water, surfactants line up in a "heads up, tails down" order, which reduces surface tension at the interface. The more surfactants there are in a liquid, the lower the surface tension when combined with another fluid. Soap detergent is one of the most common products containing surfactants, and that slippery feeling when the detergent mixes with water comes from the surfactants doing their job. In a NASA-funded research project, Stebe examines how drops and bubbles move through fluids, and how they are affected by surfactants at interfaces.

Stebe is also interested in the behavior of naturally-occurring surfactants such as lipids and proteins. Newborns need a type of lung surfactant in order to begin breathing normally. Surfactants are also present in biomembranes. Pharmaceutical companies study the characteristics of those membranes to develop techniques to transfer drugs efficiently into cells. Currently Stebe is working with graduate student Greg Troiano and Leslie Tung, an associate professor of biomedical engineering, to determine how to use an electric field to create transient pores in a membrane as a function of the type and amount of surfactant present.

Engineer Examines the Many Facets of Polymers

A southern California native, Assistant Professor John van Zanten was the first in his family to attend college. He studied chemical engineering at the University of California, Los Angeles, earning a bachelor of science degree in 1986 and a doctoral degree in 1992. "My training in what I consider to be a key engineering discipline gave me excellent preparation for what I wanted to do," van Zanten says. He received a two-year postdoctoral research associate award from the National Research Council and the National Institute of Standards and Technology (NIST).

With interests in complex fluids (fluids such as milk and shaving cream, which are built of molecular chains or aggregates rather than simple molecules) and the behavior of polymers at interfaces, van Zanten has developed several fascinating research projects. In one collaborative project with NIST, van Zanten studies polymers near the interface of glass fibers, with possible applications in the composites and microelectronics industry. In another activity, he examines polymers in supercritical solvents with Professor Mark McHugh. Van Zanten is particularly interested in the use of carbon dioxide, a benign substance that could ultimately replace the toxic organic solvents currently used in many industries. Van Zanten is also entering the biotechnology arena with his study of liposomes, microscopic spheres made of fatty substances. They are of particular interest in medicine because of their ability to act as artificial cells. Liposomes can carry drugs safely into the body to combat tumors, cancer, and even fungi. Van Zanten and a graduate student plan to examine the characteristics of liposomes, with the ultimate goal of developing techniques to control their size and properties.

Although van Zanten is only in his second year at the University, his teaching abilities have already been recognized. At the April Convocation ceremonies, van Zanten received the Robert B. Pond, Sr. Excellence in Teaching Award, named after the respected professor emeritus of materials science and engineering.