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Events
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Oct8
EVENT DETAILS
lessThe Department of Chemical and Biological Engineering is pleased to welcome Zhen-Gang Wang from the California Institute of Technology for a seminar titled:
Self-Assembly of End-Charged Block Copolymers and Blends: Effects of Ion Clustering
ABSTRACT: Adding ionic groups to polymer chain ends—whether within a single diblock copolymer or across two different homopolymers in a blend—offers a promising route to direct self-assembly for applications ranging from compatibilizing immiscible polymer blends to templating functional and ion-conducting nanostructures. Using self-consistent field theory that accounts for strong ion correlations, we show that under low-dielectric conditions typical for polymers, charged ends aggregate into multi-ion clusters that fundamentally alter assembly behavior. In end-charged diblock copolymers, these clusters act as compact, curvature-favoring foci, enabling complex network phases such as single primitive and single gyroid—structures that are absent in neutral diblocks. In binary blends with oppositely charged ends, electrostatic attraction suppresses macroscopic phase separation and induces microphase separation. However, the resulting phase diagram is simpler (dominated by lamellar and cylindrical phases) than the effective diblock picture would predict. This difference arises because ion clusters reside at the interface in blends, where they resist curvature, unlike in diblocks where they organize the surrounding chains. Notably, both systems form ordered microstructures at significantly lower segregation strengths than the corresponding uncharged diblock copolymers.
Zhen-Gang Wang received his B.Sc. in Chemistry in 1982 from Beijing (Peking) University, and his Ph.D. in Chemistry in 1987 from the University of Chicago. He did postdoctoral research first in Exxon Research and Engineering Company and then at UCLA. Since 1991 he has been on the Chemical Engineering faculty at the California Institute of Technology, where he is currently the Dick and Barbara Dickinson Professor. He has also served as Executive Officer (department chair) for Chemical Engineering for 6 years.
Wang’s research is the theoretical and computational study of structure, phase behavior, interfacial properties and dynamics of polymers, soft materials, and biophysical systems. His current activities revolve around three main themes: charged systems, including polyelectrolytes, salt-doped polymers, and electric double layers; nucleation or more generally barrier crossing in polymers and soft matter; and nonlinear rheology of polymer gels and entangled polymers.
Wang is a fellow of the American Physical Society and a member of the U. S. National Academy of Engineering. He is recipient of several significant awards and honors, including the Camille Dreyfus Teacher–Scholar Award (1995), the Alfred P. Sloan Award (1996), the Braskem Award from the American Institute of Chemical Engineers (AIChE) (2018), the AIChE Alpha Chi Sigma Award (2023), and the American Physical Society Polymer Physics Prize (2024). In addition, he was awarded the Richard P. Feynman Prize for Excellence in Teaching (2008), Caltech’s highest teaching honor.
Wang has served on the editorial advisory boards of Journal of Theoretical and Computational Chemistry, Macromolecules, ACS Macro Letters, Giant, Acta Physicochimica Sinica, and Science in China B (Chemistry). He is currently an associate editor for the ACS Journal Macromolecules.
Dr. Wang's seminar will be hosted by Northwestern faculty, Krishna Shrinivas.
TIME Thursday, October 8, 2026 at 9:30 AM - 10:45 AM
LOCATION LR4, Technological Institute map it
CONTACT Olivia Wise olivia.wise@northwestern.edu EMAIL
CALENDAR McCormick-Chemical and Biological Engineering (ChBE)
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Oct15
EVENT DETAILS
lessThe Department of Chemical and Biological Engineering is pleased to present a seminar with department faculty member, John Torkelson.
"Upcycling Virgin and Waste Thermoplastic Polyethylene, Polypropylene, and Related Copolymers into Covalent Adaptable Networks that Recover Crosslink Density upon Recycling"
ABSTRACT: Approximately one trillion pounds of synthetic polymers/plastics are produced worldwide each year. However, less than 10% of spent polymers and plastics are effectively recycled. Polyethylene (PE) and polypropylene (PP) account for more than half of global polymer production; thus, approaches to address this recycling crisis should consider PE, PP, and their copolymers. We will describe how thermoplastic PE, PP, and associated copolymers, composed of linear or branched chains, can be upcycled into covalent adaptable networks (CANs) using a one-step, radical-based reactive processing method that is a simple “drop-in” modification of the commercial process used to make non-recyclable, permanently crosslinked PE (PEX) networks or thermosets from thermoplastic PE. The commercial process for making PEX thermosets, which have enhanced properties relative to thermoplastic PE and are produced at ~20 billion pounds annually, involves melt-processing PE with a low level of radical initiator, resulting in the transfer of a hydrogen atom from PE to the initiated radical. This transfer leaves a radical on the PE backbone that can react with another PE backbone radical, leading to a permanent crosslink. We developed dynamic covalent cross-linkers that can be “dropped into” the reactive process at several weight percent relative to PE or ethylene-based copolymer. This yields CANs with crosslinks that are robust under use conditions but dynamic during melt reprocessing, enabling recyclability. Our dynamic covalent crosslinkers yield PE CANs that recover the original crosslink density and properties after multiple recycling steps and exhibit markedly reduced elevated-temperature creep compared with thermoplastic PE. We will also show that direct free-radical copolymerization of ethylene with low levels of dynamic covalent crosslinkers can produce fully recyclable PE CANs. Our approach also enables us to overcome the challenge of forming networks by reactive melt-state processing of PP and propylene-based copolymers. No commercial crosslinked PP thermoset is produced by radical-based reactive processing because of chain scission. We overcame this problem by developing methods that stabilize radicals via resonance, yielding recyclable PP CANs that recover cross-link density upon recycling. Finally, we will discuss using CANs to mitigate the formation of microplastics.
John Torkelson is a Walter P. Murphy Professor in the Dept. of Chemical and Biological Engineering and the Dept. of Materials Science and Engineering at Northwestern University. He previously served as Associate Dean for Graduate Studies and Research in the Engineering School and Director of the Materials Research Center at Northwestern. He also held leadership roles in the Division of Polymer Physics of the American Physical Society and the Materials Engineering and Sciences Division of the American Institute of Chemical Engineers. John received the Tau Beta Pi Outstanding Teaching Award, the Lilly Foundation Teaching Award, the Northwestern University Alumni Association Excellence in Teaching Award, and both the McCormick School of Engineering Teacher of the Year Award and Advisor of the Year Award. In 2004, John’s research excellence was recognized with both the Wiley Polymer Physics Award and the Charles M. Stine Award from the Materials Division of AIChE. In 2025, he was named a “highly ranked scholar”by ScholarGPS in several categories based on lifetime achievement, including #1 in “Transition Temperature,” #1 in “Gradient Copolymer,” and #3 in “Glass Transition.” John was the 2026 Turner Alfrey Visiting Professor at Michigan State University-St. Andrews, and he and his research team were just named winners of the 2027 ACS PMSE Division Cooperative Research Award for the research he will discuss in his seminar at Northwestern University.
TIME Thursday, October 15, 2026 at 9:30 AM - 10:45 AM
LOCATION LR4, Technological Institute map it
CONTACT Olivia Wise olivia.wise@northwestern.edu EMAIL
CALENDAR McCormick-Chemical and Biological Engineering (ChBE)
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Oct22
EVENT DETAILS
lessThe Department of Chemical and Biological Engineering is proud to present our 20th annual Richard S.H. Mah Lecture with speaker Jim Rawlings from the University of California, Santa Barbara.
Process Engineering at the Dawn of (Generative) AI
Maintaining high standards of living while decreasing our impact on the planet requires both new manufacturing technologies as well as increasingly efficient operation of these technologies at large scale. Process systems engineering will play a critical role in addressing these challenges.
We start with a review of some of the advances that have taken place in the field of process systems engineering during the last 50 years. We focus specifically on process control because it is currently faced with several new challenges: increasingly stringent product quality requirements, tighter environmental regulations, and increasingly transient operating conditions, e.g., large fluctuations in electricity prices and supply chains. We present the central ideas of model predictive control, which has become during this period the leading advanced feedback control method, both in industrial practice as well as a topic of control theory research. We discuss the fundamental reasons for this success, which builds upon the foundations of optimal control and dynamic modeling, supplemented with measurement feedback to make the resulting system robust against model inaccuracies and disturbances.
At the dawn of generative AI, we anticipate using machine learning and deep neural networks trained on large datasets to provide improved modeling capability. But when we create models for process optimization or process control, the basic issue to be understood is how much information are we able to extract from available measurements, and how much domain-specific structural information must we provide, e.g., conservation laws and thermodynamic principles, before the optimization of such composite models is reliable and useful. We currently lack systematic guidelines for how best to combine these two sources of information.
Finally we discuss the education of chemical engineers to understand, operate and improve these new technologies. Adding to our educational challenge, universities are now seeing the first generation of engineering students who first ask a large language model (LLM) agent to solve their homework exercises or write their software code. Meanwhile most of these exercises were designed to be solved solely by the students, to start building up their engineering understanding and intuition through simple examples. This mismatch in current educational materials and widely-available LLM technology is a pressing challenge that educators must now address.
James B. Rawlings received the B.S. from the University of Texas and the Ph.D. from the University of Wisconsin, both in Chemical Engineering. He spent one year at the University of Stuttgart as a NATO postdoctoral fellow and then joined the faculty at the University of Texas. He moved to the University of Wisconsin in 1995, and then to the University of California, Santa Barbara in 2018, and is currently the Mellichamp Process Control Chair in the Department of Chemical Engineering, and the co-director of the Texas-Wisconsin-California Control Consortium (TWCCC).
Professor Rawlings's research interests are in the areas of chemical process modeling, monitoring and control, nonlinear model predictive control, moving horizon state estimation, and molecular-scale chemical reaction engineering. He has written numerous research articles and coauthored three textbooks: "Modeling and Analysis Principles for Chemical and Biological Engineers," 2nd ed. (2022), with Mike Graham, "Model Predictive Control: Theory Computation, and Design," 2nd ed. (2020), with David Mayne and Moritz Diehl, and "Chemical Reactor Analysis and Design Fundamentals," 2nd ed. (2020), with John Ekerdt.
In recognition of his research and teaching, Professor Rawlings has
received several awards including:- Election to the National Academy of Engineering;
- John M. Prausnitz Institute Lecturer, AIChE
- Richard E. Bellman Control Heritage Award, American Automatic Control Council
- William H. Walker Award for Excellence in Contributions to Chemical
- Engineering Literature from the AIChE;
- Warren K. Lewis Award for Chemical Engineering Education from the AIChE;
- Inaugural High Impact Paper Award from the International Federation of Automatic Control (IFAC);
- Ragazzini Education Award, American Automatic Control Council;
He is a fellow of IFAC, IEEE, and AIChE.
Dr. Rawlings' Mah Lecture will be hosted by department chair Danielle Tullman-Ercek.
TIME Thursday, October 22, 2026 at 9:30 AM - 10:45 AM
LOCATION LR4, Technological Institute map it
CONTACT Olivia Wise olivia.wise@northwestern.edu EMAIL
CALENDAR McCormick-Chemical and Biological Engineering (ChBE)
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Nov5
EVENT DETAILS
lessMore details to come.
TIME Thursday, November 5, 2026 at 9:30 AM - 10:45 AM
LOCATION LR4, Technological Institute map it
CONTACT Olivia Wise olivia.wise@northwestern.edu EMAIL
CALENDAR McCormick-Chemical and Biological Engineering (ChBE)
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Nov12
EVENT DETAILS
lessMore details to come.
TIME Thursday, November 12, 2026 at 9:30 AM - 10:45 AM
LOCATION LR4, Technological Institute map it
CONTACT Olivia Wise olivia.wise@northwestern.edu EMAIL
CALENDAR McCormick-Chemical and Biological Engineering (ChBE)
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Nov19
EVENT DETAILS
lessMore details to come.
TIME Thursday, November 19, 2026 at 9:30 AM - 10:45 AM
LOCATION LR4, Technological Institute map it
CONTACT Olivia Wise olivia.wise@northwestern.edu EMAIL
CALENDAR McCormick-Chemical and Biological Engineering (ChBE)
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Dec3
EVENT DETAILS
lessMore details to come.
TIME Thursday, December 3, 2026 at 9:30 AM - 10:45 AM
LOCATION LR4, Technological Institute map it
CONTACT Olivia Wise olivia.wise@northwestern.edu EMAIL
CALENDAR McCormick-Chemical and Biological Engineering (ChBE)
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Dec12
EVENT DETAILSmore info
lessThe ceremony will take place on Saturday, December 12 in Pick-Staiger Concert Hall, 50 Arts Circle Drive.
TIME Saturday, December 12, 2026 at 4:00 PM - 6:00 PM
LOCATION Pick-Staiger Concert Hall map it
CONTACT Andi Joppie andi.joppie@northwestern.edu EMAIL
CALENDAR McCormick School of Engineering and Applied Science