ChE Seminar – “Evolutionary molecular design for scientific discovery in sequence-specific polymers and glass-forming materials” by Dr. David Simmons (University of Akron)

Host: Dr. Isaac Sanchez


The last decade has seen the emergence of a new frontier in polymers: the facile synthesis of copolymers with specific monomeric sequences. This may be the key to realizing synthetic polymers exceeding the performance of biopolymers such as proteins and DNA. Achieving this goal will require solutions to two challenges. First, the design space afforded by even a single sequence-specific polymer can be beyond astronomical in scale. How are we to reproduce the billions of years nature has dedicated to designing these complex molecules? Second, the last century of polymer physics has focused on establishing theoretical understanding at the level of mean chain composition or statistical descriptions of sequence. Realizing a new generation of sequence-specific polymeric materials demands a reimagining of polymer theories to understand the behavior of sequence-specific polymers.  More broadly, this problem represents an extreme case of the challenge of soft materials design, where chemical design spaces are large and predictive theoretical understanding often lacking.

Here I describe a new approach to this problem, combining molecular dynamics simulations, machine learning, and evolutionary algorithms to design sequence-specific polymers with extremal properties and then reverse-engineer their underlying physics. We apply this strategy to design model sequence-specific copolymer compatibilizers that reduce the energy of a polymer/polymer interface more efficiently than sequence-nonspecific surfactants. Study of these designed sequences ultimately yields new physical insight into the role of chain sequence in polymer surfactants. Finally, we demonstrate that this strategy for materials design and understanding is extensible to the design and understanding of other classes of soft materials.


Assistant Professor of Polymer Engineering

  • Ph.D. in Chemical Engineering, University of Texas at Austin (2009)
  • B.S. in Chemical Engineering, University of Florida (2005)

The Simmons group employs theory, molecular simulation, optimization methods, high-throughput characterization, and machine learning to advance the understanding and design of polymers and other soft materials. Specific areas of interest include:

  • Computational design of polymers with targeted dynamics, mechanics, and glass formation behavior
  • Physics of the glass transition
  • Dynamic and mechanical properties of nanostructured polymers and polymer films
  • Design principles for advanced molecular additives for use in polymers
  • Molecular strategies for enhanced toughness and dynamic mechanical response in elastomers
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