Lehigh University logo
Lehigh University logo
Lehigh University logo

Sabbatical benefits researcher and his students

Fresh off a sabbatical at Caltech, Jim Gilchrist is finding considerable interest in his research on particle coatings and the structure of suspensions. This summer, he will deliver invited keynote presentations on particle coatings at conferences in Washington, D.C., and Shanghai. Recently, he’s given talks in Lisbon and North Carolina on his work with suspensions, and he will give another lecture on that topic in Denmark in the near future.

His colleagues at Caltech were particularly interested in the results that Gilchrist, an associate professor of chemical engineering, has achieved in the field of suspension microstructural characterization. Using confocal laser scanning microscopy, he and his group track particles in 3-D solutions to determine their “fingerprint” and to understand how structure relates to the unusual properties of complex fluids. They strive to obtain simulation-level detail from these nanoscale measurements and use them to calculate internal stresses.

The measurements promise to enable the design of complex fluids whose properties are useful in the pharmaceutical, chemical, agricultural, food, cosmetic, ceramic, electronic and mining (hydraulic fracturing) industries. They could also shed light on natural processes like transport sediment in rivers and blood flow.

Graduate student M. Tharanga Perera, who measures suspension stress during flow, has reported unexpected particle ordering when polymer is added to solution. “The work has motivated him to produce perhaps the most accurate measurements to date of these systems,” says Gilchrist.

Alexander Weldon, a fifth-year undergrad, has given several conference presentations on the coatings research he conducts with Gilchrist. These experiences have strengthened his aspiration to be an astronaut.

“The opportunities to network and to collaborate with faculty on research,” says Gilchrist, “help pave the way for students like Tharanga and Alex to move into the next stages of their careers.”

At Caltech, Gilchrist was hosted by John F. Brady, the Chevron Professor of Chemical Engineering, who studies novel simulations of suspensions. “The experience was inspirational,” says Gilchrist. “Brady and the entire chemical engineering faculty were incredibly welcoming and supportive.”

The sabbatical also connected Gilchrist with Harry Atwater, director of Caltech’s Light-Material Interactions Energy Frontier Research Center. Gilchrist and Atwater are developing microlens array coatings for silicon solar cells, mirroring a similar project Gilchrist has with Mark Snyder, the P.C. Rossin Assistant Professor of Chemical Engineering at Lehigh.