In Memoriam: Don Sullivan

Don Sullivan 1950 – 2026

The department mourns the passing of Professor Emeritus Donald Sullivan on 29 July 2026 from complications related to COPD.  We extend our condolences to his niece and nephews.  Don was born in Montreal and received his first degree in Chemistry from McGill University in 1972 and his doctorate from the Massachusetts Institute of Technology in Physical Chemistry in 1976 under the supervision of J.M. Deutch. He was a post-doc at SUNY in Stony Brook, New York and followed that with a research associateship at the National Research Council in Ottawa.  He joined the Department of Physics at Guelph in 1978 as assistant professor, became associate professor in 1983 and full professor in 1990.  His research interests were broadly centered in statistical mechanics and on critical phenomena, and he was well known for his pioneering theoretical work on liquid crystals and for his important contributions to the density functional theory of complex fluids.  His later work focused on exploring models of smectic (layered) liquid crystals in systems of semiflexible polymers.  His thoughtful and substantial contributions as a journal referee (10 to 15 papers per year) were recognized with an Outstanding Referee Award by the American Physical Society in 2008.  Students found Don to be both approachable and engaging, resulting in a steady stream of graduate students.  This interaction led to his being graduate coordinator for nine years and director of the joint Guelph-Waterloo Physics Program for three years (2002-05).  Several of his students became professors at Canadian universities and an early post-doc from Madrid became a professor there maintaining a collaboration lasting several decades.  His teaching duties included serving as the instructor for both the undergraduate and graduate statistical mechanics courses, Mechanics II, and Quantum Mechanics. Don also taught the first-year Physics for the Biological Sciences course and was a co-author, along with departmental colleagues, of the widely-used textbook designed for that course.  Many of the past graduate students and departmental colleagues have fond memories of the parties at his renovated brick house in Guelph’s hospital district. After retirement, deteriorating health forced him to sell his house and move into assisted living at the Elliott Community in Guelph where he spent the last 11 years.