Russel, the Arthur W. Marks ’19 Professor in Chemical Engineering, Emeritus, rose to prominence as a specialist in colloids, which are suspensions of tiny particles in fluids, such as smoke or milk. His work, which included one of the classic equations of his field, helped combat pollution and led to improved paints, medicines and adhesives. He was a member of the National Academy of Engineering and the American Academy of Arts and Sciences.

He was the first author, along with colleagues Dudley A. Saville and William R. Schowalter, of Colloidal Dispersions, a fundamental text in the discipline. “His work was very deep and very broad,” said Pablo Debenedetti, the Class of 1950 Professor in Engineering and Applied Science.

Russel joined the Princeton faculty in 1974 and served as dean of the Graduate School for 12 years beginning in 2002, leaving an immense and lasting impact on graduate education at Princeton. Among other noteworthy accomplishments, he improved support and financial assistance for all graduate students, expanded the diversity of the graduate student body, and deepened the relationship between graduate alumni and the University. He oversaw the development of the Lakeside residential complex and pressed for the inaugural affinity conference for graduate alumni in 2013. He transferred to emeritus status in 2017 after 43 years on the Princeton University faculty.

Rodney Priestley, the current dean of the Graduate School, recalled working with Russel when he joined the Department of Chemical and Biological Engineering in 2009. As an assistant professor, Priestley saw Russel as “an extraordinary researcher who thought at an exceptionally deep and profound level but never used that to be intimidating.”

Priestley said he sees Russel’s imprint every day in the Graduate School culture. “The Graduate School is very welcoming, warm and caring,” said Priestley, the Pomeroy and Betty Perry Smith Professor of Chemical and Biological Engineering. “Those are things people have always said about Bill.”

Innovation and leadership in engineering

When Russel joined the Princeton faculty in 1974, the study of colloids was a topic of interest to several of his new colleagues. Schowalter and Saville, both professors of chemical engineering, had been pursuing research into the flow and behavior of colloids. The topic is important to many engineering disciplines, from the creation of circuits and nano materials to the separation of proteins for pharmaceuticals. Schowalter said Russel brought a mathematical approach to the effort, seeking to understand the fundamental principles that governed how colloids flowed and how they behaved under varying conditions.

The group collaborated on experiments and taught each other’s graduate students. Soon, they decided to write their book. “We used to get together on Friday afternoons, and we would give each other assignments,” Schowalter said. “We almost always held the meetings in Bill’s office, and there was a reason for that. Because he was the guy who made things happen.”

Richard Register, Eugene Higgins Professor of Chemical and Biological Engineering, recalled that as chair of chemical engineering, Russel recruited him to come to Princeton as a young professor. Register later also served as chair of the department, which became Chemical and Biological Engineering, and said that Russel always stood as an example of service as well as scholarship.

“Bill set a real example,” Register said. “He always did what needed to be done.”

Register, who is now the director of the Princeton Materials Institute, said Russel played a key role in the development of the institute, serving as the second director. “Bill was one of the handful of people who really laid the groundwork” for the modern institute, which now includes some of the world’s most sophisticated facilities for microscopy and for the fabrication of atomic-scale structures needed in research and industry, Register said.

Debenedetti, the former dean for research, said that Russel specialized in understanding the dynamics of colloids, how they behave and move over time, as well as their microscopic structure.

“Colloids are tiny particles suspended in another medium, generally a liquid,” said Debenedetti, a professor of chemical and biological engineering. “They find applications in many fields – industrial waste treatment, protein separations, food science, cosmetics, paints, pharmaceuticals.”

Work by Russel and colleagues helped engineers to control suspended particles. That can be useful when keeping particles in suspension for foods such as ketchup or mayonnaise or when controlling how suspended particles settle to form crystals or other delicate structures for industries such as pharmaceuticals or electronics. Debenedetti said that Russel also explored the behavior of colloids in microgravity and collaborated on a series of classic experiments with Paul Chaikin, professor of physics, emeritus, that were conducted in space.

Debenedetti said that some of Russel’s most influential work was conducted with then-graduate student Alice Gast, who went on to become the president of Imperial College London, and colleague Carol Hall, now the Camille Dreyfus Distinguished University Professor of Chemical and Biomolecular Engineering at North Carolina State University.

“He formulated a theory that has become a classic in which he laid down the basic principles for stabilizing colloids in suspension using polymers,” Debenedetti said.

Collaborating across disciplines, seeding ‘Russel Sprouts’

Gast said the project was memorable in part because collaborations crossing scientific disciplines were not typical at the time.

“Bill had found an interesting phenomenon from the paint industry where mixtures of colloidal particles and polymer molecules caused a weak and reversible aggregation of the particles,” said Gast. The group worked on a model to explain and predict the long-range interactions between the colloids as they bump around in suspension with the polymers. “Carol’s statistical mechanical approaches allowed us to map phase diagrams for these suspensions; and the theory worked!”

Gast, now professor of chemical engineering, emeritus, at Imperial College, said the experience instilled a lifelong appreciation for collaboration. “Bringing together researchers from different backgrounds through a shared intellectual curiosity is very powerful,” she said.

Udit Batra, who earned his doctorate in chemical engineering in 1996, recalled that Russel’s students referred to themselves as “Russel Sprouts.”

“While Bill’s intellectual contributions and his mentorship are indisputable, what stood out to me was his patience and his contribution to my growth,” said Batra, now president and CEO of the Waters Corporation. “It was a privilege to be a Russel Sprout.”

Batra and Gast both said that Russel treated his students as colleagues and, while he set high standards, he allowed them space to find solutions to problems. Batra recalled spending six months on an experiment that was not working. He said he would meet with Russel and discuss the challenges he was facing. Instead of suggesting solutions, Russel told him to exhaust all possibilities.

“Bill said maybe it’s the equipment,” Batra said.

Batra eventually disassembled sophisticated lab equipment including a laser and a rheometer and taught himself how to put them back together. It turned out the laser was malfunctioning. Today, Batra leads a company that manufactures both instruments.

“That is what the Ph.D. is about. It is not about solving a specific problem. It is about becoming a problem solver,” Batra said. “In moments where you have an apparent failure, lies the opportunity to really learn how to problem solve.”

Lasting impact on graduate education

Russel was the first engineer to serve as dean of the Graduate School, where he guided the creation of two significant academic advances: the student re-enrollment process – a framework for providing early guidance to students encountering challenges with their theses – and the Doctoral Completion Enrollment (DCE) status. The DCE status allows students extra time to finish their dissertations while retaining student benefits such as University housing and health plan eligibility, international student visas, and loan deferments.

Former students and colleagues at the Graduate School remember him as a leader who brought to his role a profound intellect, an engineer’s analytical precision and insight, and deep care and concern for others.

“The creation of DCE status helped reduce barriers for students to get their degrees,” said Deputy Dean Lisa Schreyer, who worked in student affairs when Russel was dean. “Bill championed so many things that enhanced the quality of life of our students. He was a kind person and not one who sought the spotlight for himself. He quietly advanced the principles he wanted to move forward.”

Anthony Fiori, who received his master’s degree from the School of Public and International Affairs in 2003, worked with Russel as a member of the Graduate Student Government. Fiori, now a senior managing director with Manatt Health, fondly remembers one of their first efforts: upgrading the chairs in the Graduate College. “You would literally be sitting in these chairs and falling through.”

Although they would go on to work on more significant projects, Fiori said that first upgrade was emblematic of Russel’s attention to detail and concern for graduate students’ experience at Princeton. “Bill was a staunch advocate for investments in graduate students and student life.”

Fiori continued to work with Russel as a board member and president of the Association of Princeton Graduate Alumni (APGA.) “Bill never missed an APGA meeting,” he said. “He was always prepared. The first graduate alumni conference would not have happened without Bill. He saw the vision. When I look back on my time as a volunteer, one of the things I really cherish was the relationship I had with Bill.”

Priestley said his early-career exposure to Russel’s leadership left an impression. He recalled dinners that Russel and his wife, Priscilla, would host for department members at their home on the grounds of the Graduate College. “Their warm hospitality gave me great opportunities to talk with Bill and my colleagues and introduced me to the idea of being dean of the Graduate School much earlier than I would have thought about it,” said Priestley.

Cole Crittenden, now vice provost for academic affairs, said Russel recognized how much graduate alumni wanted to be more connected to Princeton, and he “found the right ways to strengthen those connections,” including drawing on their expertise and input.

Crittenden joined the Graduate School near the end of Russel’s term as dean. He said Russel built a strong leadership team that improved graduate education across the board. “It was a privilege to be part of the team that he built, and it is still one of the highlights of my professional life,” he said.

Karen Jackson-Weaver, Class of 1994, worked with Russel as associate dean for academic affairs and diversity, supporting the academic progress of all graduate students. She said Russel was committed to fostering the inclusion of historically underrepresented groups in the graduate school, including first-generation students and women in science, engineering and math. Jackson-Weaver, now a senior associate vice president at New York University, said Russel knew it wasn’t just about getting students into graduate school; it was about supporting them once they were at Princeton and enabling their careers.

“A whole ecosystem of support, collaboration, and engagement initially started as conversations that Bill and I had in our weekly one-on-one meetings,” she said. “Bill was committed to each and every student, and he was committed to supporting the whole student.”

Russel was born in Corpus Christi, Texas, in 1945. He received his bachelor’s and master’s degrees in chemical engineering from Rice University and his doctorate in chemical engineering from Stanford University. He joined the Princeton faculty in 1974.

He served as chair of the Chemical Engineering Department for nine years and director of the Princeton Materials Institute from 1996-1998. He was principal investigator for the Princeton Center for Complex Materials (PCCM), a materials research science and engineering center. In addition to his national academy memberships, he was president of the Society of Rheology and a fellow of the American Association for the Advancement of Science.

Among many other professional honors, Russel was the recipient of the Bingham Medal from the Society of Rheology, the William H. Walker Award for Excellence in Contributions in Chemical Engineering Literature, and the Alpha Chi Sigma Award for Chemical Engineering Research, both from the American Institute of Chemical Engineers.

He is survived by Priscilla Griffiths Russel, his wife of 51 years; his son Daniel (Class of 1999), daughter-in-law Lena Temov Russel, and grandson Kai of Palo Alto, California; his son Bailey (Class of 2001), daughter-in-law Annika Walters (Class of 2002), and granddaughter Katla of Laramie, Wyoming; and his sister, Mary Russel Keath, of Bend, Oregon.

The family asks that charitable contributions in Russel’s name be directed to the William B. Russel Fund for Chemical and Biological Engineering, Princeton University, P.O. Box 5357, Princeton, N.J. 08543-5357 or to Somos Amigos Medical Missions, P.O. Box 29196, San Juan, Puerto Rico, 00929.

View or share comments on a memorial page intended to honor Russel’s life and legacy.