Dr. James Spiros Vrentas

April 14, 1936 - August 7, 2025

State College, Pennsylvania - Dr. James Spiros Vrentas, Dow Professor Emeritus of Chemical Engineering, passed away on Aug. 7, 2025. He was a devoted husband and father and a brilliant yet humble teacher and researcher.

Jim was born on April 14, 1936, in Danville, Ill., the son of Greek immigrants Spiros and Evanthia (Gintonis) Vrentas. As his father passed away when Jim was only five, to help support his family, he began carrying the Danville daily newspaper, The Commercial-News, in fifth grade until he graduated from high school and was awarded the Frank Gannett Newspaper Boy Scholarship. His paper route of almost 150 papers was the largest in the city and was split into two routes after his graduation.

Jim graduated as valedictorian of Danville High School in 1954 and won by exam an Illinois State Scholarship to attend the University of Illinois Urbana-Champaign, where he studied chemical engineering. He graduated with highest honors in 1958, and his name is inscribed on a Bronze Tablet in the U of I Main Library. He was a member of Alpha Chi Sigma, Tau Beta Pi, and Phi Kappa Phi. Jim won a National Science Foundation Graduate Research Fellowship to study at the University of Delaware, where he earned his M. ChE. in 1961 and Ph.D. in chemical engineering in 1963.

Jim worked in the Process Fundamentals Lab at the Dow Chemical Company in Midland, Mich., from 1963-72, and then was a professor of chemical engineering at the Illinois Institute of Technology for eight years. In 1980, he joined the Department of Chemical Engineering at Penn State, where he taught and did research for 36 years until his retirement in 2016. He continued his research after his retirement.

For his research on diffusion and fluid mechanics, including the free volume theory of diffusion, Jim was awarded the American Institute of Chemical Engineers' William H. Walker Award for Excellence in Contributions to Chemical Engineering Literature (1981) and the Charles M.A. Stine Materials Engineering and Science Award (1989), as well as the Penn State Engineering Alumni Society's (PSEAS) Outstanding Research Award (1984) and Premier Research Award (1991). As a teacher, he had a unique ability to make difficult concepts easily understandable. He was awarded PSEAS's Outstanding Teaching Award (1985) and was named Outstanding Professor by chemical engineering graduate students from 1983-85. (The award was discontinued in 1985, in part because the students said he would keep winning it as long as he taught them.) In 1985, he was appointed the Dow Professor of Chemical Engineering.

Jim has authored more than 170 refereed articles. Together with his wife, Christine, an adjunct professor, he wrote a 644-page graduate-level transport book, "Diffusion and Mass Transfer" (2013).

In 1975, Jim married Christine (Jarzebski) Vrentas, who survives along with their two daughters, Catherine and Jennifer. Jim enthusiastically supported his children's interests, coaching their Science Olympiad and softball teams, serving as a lane timer at their swim meets and being their math and physics resource. Both of his girls followed in his footsteps - Cathy earned a Ph.D. in cell and molecular biology, while Jim's stint as his high school newspaper's sports editor helped inspire Jenny's journalism career. Jim particularly enjoyed his daily afternoon runs.

In addition to his parents, his sister, Toula S. Vrentas, predeceased him. He is also survived by his cousins Ellen (Jerry) Walker, George (Jane) Vrentas, and Steve Vrentas. Jim was of the Greek Orthodox faith.

Donations in his memory can be made to the Penn State University Department of Chemical Engineering General Scholarship fund: http://raise.psu.edu/RememberingJamesVrentas. Alternatively, contributions can be made by check payable to the Pennsylvania State University with the code SCDCC written in the memo line of the check and a note that it's to support the Department of Chemical Engineering General Scholarship fund in memory of Dr. James Vrentas. Checks can be sent to Donor and Member Services, 329 Innovation Blvd, Suite 311, State College, PA 16803.