Joseph Tracy

University Faculty Scholar and Professor

Many kinds of nanoscale materials have size- and shape-tunable physical properties arising from their reduced dimensions and high surface-area-to-volume ratio. We synthesize magnetic and noble metal nanoparticles using a “bottom-up” approach starting from molecular precursors. Surface modification of nanoparticles with organic molecules and inorganic overcoatings imparts additional chemical, physical, and biological functionality. The surface plasmon resonance of gold nanoparticles depends on their shape and is sensitive to interparticle coupling. Magnetic nanoparticles have size-dependent magnetic properties and can be manipulated with magnetic fields, for example to direct assembly into chains. Incorporating magnetic and plasmonic nanoparticles into soft polymers makes possible remote actuation with magnetic fields and light.

Dr. Tracy’s research interests include the synthesis, characterization, and self-assembly of noble metal, magnetic, and multifunctional nanoparticles and their applications in soft robotics, sensors, and medicine.


Magnetic Reprogramming of Self-Assembled Hard-Magnetic Cilia
Clary, M. R., Cantu, S. N., Liu, J. A.-C., Evans, B. A., & Tracy, J. B. (2024, April 22), ADVANCED MATERIALS TECHNOLOGIES.
Movement with light: Photoresponsive shape morphing of printed liquid crystal elastomers
Ford, M. J., Porcincula, D. H., Telles, R., Mancini, J. A., Wang, Y., Rizvi, M. H., … Cook, C. C. (2024), MATTER, 7(3).
Solvent Effects in Ligand Stripping Behavior of Colloidal Nanoparticles
Mahmood, A. U., Rizvi, M. H., Tracy, J. B., & Yingling, Y. G. (2023, June 13), ACS NANO, Vol. 6.
Dynamics of dual-junction-functionality associative polymer networks with ion and nanoparticle metal-coordinate cross-link junctions
Song, J., Li, Q., Chen, P., Keshavarz, B., Chapman, B. S., Tracy, J. B., … Holten-Andersen, N. (2022), JOURNAL OF RHEOLOGY, 66(6), 1333–1345.
Magnetic Alignment for Plasmonic Control of Gold Nanorods Coated with Iron Oxide Nanoparticles
Rizvi, M. H., Wang, R., Schubert, J., Crumpler, W. D., Rossner, C., Oldenburg, A. L., … Tracy, J. B. (2022, September 1), ADVANCED MATERIALS, Vol. 9.
Microscopic dynamics underlying the stress relaxation of arrested soft materials
Song, J., Zhang, Q., Quesada, F., Rizvi, M. H., Tracy, J. B., Ilavsky, J., … McKinley, G. H. (2022), PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 119(30).
Size control of cobalt nanoparticles by adjusting the linear carboxylic acid ligand chain length
Johnston-Peck, A. C. C., & Tracy, J. B. B. (2022), JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 550.
Controlled Organization of Inorganic Materials Using Biological Molecules for Activating Therapeutic Functionalities
Chandler, M., Minevich, B., Roark, B., Viard, M., Johnson, M. B., Rizvi, M. H., … Afonin, K. A. (2021), ACS APPLIED MATERIALS & INTERFACES, 13(33), 39030–39041.
Flexible Cyclic-Poly(phthalaldehyde)/Poly(epsilon-caprolactone) Blend Fibers with Fast Daylight-Triggered Transience
Li, S., Rizvi, M. H., Lynch, B. B., Tracy, J. B., & Ford, E. (2021), MACROMOLECULAR RAPID COMMUNICATIONS, 42(7).
Plasmon-Coupled Gold Nanoparticles in Stretched Shape-Memory Polymers for Mechanical/Thermal Sensing
Yadav, P. R., Rizvi, M. H., Kuttich, B., Mishra, S. R., Chapman, B. S., Lynch, B. B., … Tracy, J. B. (2021), ACS APPLIED NANO MATERIALS, 4(4), 3911–3921.

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Joseph Tracy