​B.S. Boston University, 1991​M.S. University of Maryland, 1997​Ph.D. University of Maryland, 2001

Our research group focuses on the synthesis of well-defined nanoparticles, their dispersion into polymer solutions and melts, and their suspension rheology.

First, we study the mechanisms that produce well-defined nanoparticles and then use this knowledge to optimize for a range of industrially relevant properties such as particle stability, surface expression, or catalytic activity. We are also interested in developing timely methods for determining nanoparticle growth rates inside of emulsions which are used in formulating a variety of commercial products like fiber-optic coatings, automotive finishes, and chromatographic packings.

Second, we examine how grafting uniform polymers to the interfaces of well-defined nanoparticles affects their rheological behavior in polymer solutions and melts. With our fundamental studies, we seek to optimize processing to achieve a desirable microstructure in industrial suspensions, and to set a foundation for developing constitutive rheological models that predict the complex behavior of industrial suspensions. To this end, we use rheological and rheo-optical measurements to elucidate how the interactions within model suspensions affect their flow at nano-, micro-, and macroscopic length scales the full range of interactions that effect the processing of engineered materials.


  • Visiting Researcher, Forschungszentrum Jülich (Jülich Research Center in Germany) 2013
  • NSF CAREER Award 2007-2012
  • NSF International Research Fellow, Katholieke Universiteit Leuven, Belgium 2003-2004

Research Interests

  • Colloids and Interfaces
  • Assembly and Rheology
  • Soft Materials and Soft Matter

In the News

Selected Publications

  • Theoretical and Experimental Investigation of Microphase Separation in Mixed Thiol Monolayers on Silver Nanoparticles, ACS Nano, 10, 9871-9878 (2016) S.N. Merz, Z.J. Farrell, C.J. Dunn, R.J. Swanson, S.A. Egorov, and D.L. Green
  • “Development of Experiment and Theory to Detect and Predict Ligand Phase Separation on Silver Nanoparticles,” Angewandte Chemie, 54, 6479–6482 (2015) Z. Farrell, S. Merz, J. Seager, C. Dunn, S. Egorov, D.L. Green
  • “Thermal and Rheological Behavior of Polymer Grafted Nanoparticles,” Macromolecules, 48, 8651–8659 (2015) D.F. Sunday and D.L. Green
  • “Quantification of Nanoparticle Interactions in Pure Solvents and a Concentrated PDMS Solution as a function of Solvent Quality,” Langmuir, 29, 9991-10000 (2013) N. Dutta, Y. Yang, Sergei Egorov, and D.L. Green
  • “A Straightforward, One-Step Synthesis of Alkanethiol Capped Silver Nanoparticles,” Langmuir, 29, 9291-9300 (2013) Z. Farrell, and C. Shelton, C. Dunn, D.L. Green
  • “A Phase Diagram for Polymer-Grafted Nanoparticles in Homopolymer Matrices,” Macromolecules, 45, 4007–4011 (2012) D. Sunday, J. Ilavsky, D.L. Green