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Robert Ivancic (Fed)


Mechanics of macromolecules

When polymer materials are stretched, they bend, deform, and ultimately break. How do we understand this process and control it to yield better materials? This project explores how glassy structure, crystallinity, and entanglements affect polymer mechanics. Employing computational, theoretical, and data-science-driven techniques, we develop next-generation plastics and compatibilizers. This work is in conjunction with NIST's Polymer Analytics and Circular Economy projects.

Dilute solution polymer properties

While branched polymers have many technological applications, the structural characterization of these polymers poses experimental challenges. Though many theories assume a single, well-defined structure, synthesizing these macromolecules produces a wide distribution of architectures. Using in silico methods can solve these issues by allowing precise structural control and rapid fabrication of new materials. We generate relationships between polymer architecture and dilute solution properties, such as the intrinsic viscosity, radius of gyration, and hydrodynamic radius. Working closely with experiments, we plan to use these relationships to improve recycling techniques. This work is part of NIST's Macromolecular Architectures and Circular Economy projects.

Non-nist publications

A selection of non-NIST publications is provided below. A complete list is available on my Google Scholar. * co-first authorship. 

  • Robert J. S. Ivancic and Robert A. Riggleman. "Dynamic phase transitions in freestanding polymer thin films." Proceedings of the National Academy of Sciences 117.41 (2020): 25407-25413.
  • Robert J. S. Ivancic and Robert A. Riggleman.  "Identifying structural signatures of shear banding in model polymer nanopillars." Soft matter 15.22 (2019): 4548-4561.
  • Cubuk, Ekin D.*, Robert J. S. Ivancic*, Sam S. Schoenholz*, Daniel J. Strickland* et al. "Structure-property relationships from universal signatures of plasticity in disordered solids." Science 358.6366 (2017): 1033-1037.




MML Postdoctoral Fellow Accolade for "Outstanding modeling of polyolefins in support of the circular economy", 2022


Created August 5, 2020, Updated February 21, 2023