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Robert Ivancic (Fed)
RESEARCH INTERESTS
Improved polymer spectroscopy
Spectroscopy measurements often contain a mixture of pure component signals of unknown shape and concentration. An important measurement challenge is how to deconvolute these pure component signals given a limited set of experiments and how to use this data to improve machine learning models. This project focuses on using signal processing techniques, machine learning, and AI explainability to improve polymer spectroscopy. This work is done with NIST's Polymer Analytics project.
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 project.
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 U.S. industrial competitiveness through better plastic characterization. This work is part of NIST's Macromolecular Architectures project.
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.
Awards
NIST Sigma Xi Early-Career Poster Presentation for outstanding poster, 2023
MML Postdoctoral Fellow Accolade, 2022