The Warren K. Lewis Lectureship in Chemical Engineering – 2023

Atomistic and Mesoscopic Modeling of Structure-Property Relations in Polymers

Doros Theodorou MS ’83 PhD ’85
National Technical University of Athens

Friday, March 24, 2023
3:00 p.m., Room 66-110
Massachusetts Institute of Technology
Cambridge, MA
[Lecture Video]

Technical Lecture:
Thursday, March 23, 2023, 4:00 p.m. in 66-110
Multiscale Modeling of Polymers at Interfaces and Polymer-Matrix Nanocomposites


Molecular-based approaches for understanding and tailoring structure-property-processing relations in materials, based on the fundamental principles of quantum and statistical mechanics, have gained ground in academic research and industrial practice.  They have been greatly aided by an unprecedented growth in computer power, but also by new, efficient  theoretical and computational methods and algorithms.   The broad spectra of length and time scales governing structure and dynamics in real-life materials have demanded the advancement of multiscale modeling strategies, involving several levels of representation, to bridge atomistic constitution and interactions with macroscopic properties.

In this talk we will discuss three examples of molecular modeling of structure-property relations in polymeric materials: (a) prediction of linear and nonlinear rheological properties of high-molecular weight polymer melts, such as polyethylene and cis-1,4 polyisoprene, through hybrid particle-field mesoscopic simulations employing slip-springs to represent entanglements and parameterized on the basis of atomistic calculations; (b) tracking structural relaxation in polymer glasses, such as polystyrene, as a sequence of elementary transitions between basins on their energy hypersurface, with transition rate constants computed from atomistic infrequent-event analysis; (c) quantifying the morphology developing upon crystallization of polyethylene films formed from the melt through the Machine Direction Orientation process.  In each example we will outline how scale-hopping algorithms can be devised, based on rigorous statistical mechanical principles, to meet the challenges of long time and length scales in a computationally tractable way.  The computational results lead to property predictions that are validated by available experimental measurements and elucidate molecular-level processes that are critical to materials design.


Doros Theodorou (orcid 0000-0002-4763-9739, Google Scholar) is Professor of Chemical Engineering at the National Technical University of Athens, Greece (NTUA).  He holds a Diploma from NTUA (1982), and M.S. (1983) and Ph.D. (1985) degrees from MIT.  He has served as professor at the Universities of California, Berkeley (1986-1995) and Patras (1991-2002) and associated faculty at the Lawrence Berkeley Laboratory, FORTH/ICE-HT in Patras and NCSR “Demokritos” in Athens.

His research focuses on the development of new computational techniques for understanding and predicting properties of materials based on their chemical constitution, with emphasis on polymers, amphiphiles, and nanoporous materials.  He has authored and co-authored 198 research papers, 32 chapters in books and review articles, and the books Simulation Methods for Polymers with M.J. Kotelyanskii  and Diffusion in Nanoporous Solids with  J. Κärger και D. Ruthven.  He represented Greece to the mobility of researchers program of the European Union (1995-2004), has served as member of Panels PE8 and PE11 of the European Research Council (2015-2022) and member of the National Council of Research, Technology, and Innovation of Greece (2010-2013, 2020-).  He is also Vice President of the Bodossaki Foundation.

His research has been recognized with the Presidential Young Investigator Award of the ΝSF (1988-1992), the Science Award of the Bodossaki Foundation in Chemistry (1996), the Danckwerts Lectureship of the AIChE (2006), the D. Medema Award of the Dutch PTN (2009), the Bird-Stewart-Lightfoot Lectureship of the University of Wisconsin (2013), the John M. Prausnitz Award in Applied Chemical Thermodynamics (2016), the John M. Prausnitz AIChE Institute Lecture (2016), the European Materials Medal of the Federation of European Materials Societies (2017), the DSM Life Time Achievement Award in Materials Sciences (2018), the 2018 Guggenheim Medal of the IChemE, and the 2022 FOMMS Medal.  In 2015 he was elected member of the U.S. National Academy of Engineering.