Professor Sharon C. Glotzer

Professor Sharon C. Glotzer, PhD, NAS, NAE
Department of Chemical Engineering
University of Michigan
Host: Professor Christy Haynes

Abstract

On the Nature of the Entropic Bond

Entropy is typically associated with disorder; yet, the counterintuitive notion that particles with no interactions other than excluded volume might self-assemble from a fluid phase into an ordered crystal has been known since the mid-20th century. First predicted for rods, and then spheres, the thermodynamic ordering of hard shapes by nothing more than crowding is now well established. In recent years, surprising discoveries of entropically ordered colloidal crystals of extraordinary structural complexity have been predicted by computer simulation and observed in the laboratory. Colloidal quasicrystals, clathrate structures, and structures with large and complex unit cells typically associated with metal alloys, or obtained in systems of interacting nanoparticles, can all self-assemble from disordered phases of identical particles due solely to entropy maximization. In this talk, we show how entropy alone can produce order and complexity beyond that previously imagined, both in colloidal crystal structure as well as in the kinetic pathways connecting fluid and crystal phases. We show how entropic forces can be directional and introduce the concept of the entropic bond. We introduce a new theory of entropic bonding and show how methods used by the quantum community to predict atomic crystal structures can be used to predict entropic colloidal crystals.

Research

The new revolution in nano-science, engineering and technology is being driven by our ability to manipulate matter at the molecular, nanoparticle, and colloidal level to create “designer” structures. Using computation, geometrical concepts, and statistical mechanics, we seek to understand complex behavior emerging from simple rules and forces, and use that knowledge to design new classes of materials.

Our introduction of the notion of “patchy particles,” a conceptual approach to nanoparticle design, has informed wide-ranging investigations of self-assembly. We showed that entropy alone can assemble shapes into many structures, which has implications for materials science, thermodynamics, mathematics, nanotechnology, biology and more. Our “shape space diagram” shows how matter self-organizes based on the shapes of the constituent elements, making it possible to predict what kind of ordered material will emerge from disorder.

Sharon Glotzer

Sharon C. Glotzer is the John W. Cahn Distinguished University Professor of Engineering and the Stuart W. Churchill Collegiate Professor of Chemical Engineering and Professor of Materials Science and Engineering at the University of Michigan, Ann Arbor, and also holds faculty appointments in Physics, Applied Physics, and Macromolecular Science and Engineering. Since July 2017 she is the Anthony C. Lembke Department Chair of Chemical Engineering at the University of Michigan. Her research on computational assembly science and engineering aims toward predictive materials design of colloidal and soft matter. Using computation, geometrical concepts, and statistical mechanics, her research group seeks to understand complex behavior emerging from simple rules and forces, and use that knowledge to design new materials. Glotzer’s group also develops and disseminates powerful open-source software including the particle simulation toolkit, HOOMD-blue, which allows for fast molecular simulation of materials on graphics processors, the signac framework for data and workflow management, and several analysis and visualization tools. (https://github.com/glotzerlab/)

Glotzer received her Bachelor of Science degree in Physics from UCLA and her PhD in Physics from Boston University. She is a member of the National Academy of Sciences, the National Academy of Engineering, and the American Academy of Arts and Sciences. She is a Fellow of the Materials Research Society, the American Association for the Advancement of Science, the American Institute of Chemical Engineers, the American Physical Society, and the Royal Society of Chemistry. Glotzer is the recipient of numerous awards and honors, including the 2019 Aneesur Rahman Prize for Computational Physics from the American Physical Society, the 2018 Nanoscale Science and Engineering Forum and the 2016 Alpha Chi Sigma Awards both from the American Institute of Chemical Engineers, and the 2019 Fred Kavli Distinguished Lectureship in Materials Science, 2017 Materials Communications Lecture Award and 2014 MRS Medal from the Materials Research Society. Glotzer is a leading advocate for simulation-based materials research, including nanotechnology and high performance computing, serving on boards and advisory committees of the National Science Foundation, the U.S. Department of Energy, and the National Academies. She is currently a member of the National Academy of Sciences Division on Engineering and Physical Sciences Committee.

Start date
Thursday, Feb. 17, 2022, 9:45 a.m.
End date
Thursday, Feb. 17, 2022, 11 a.m.
Location

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