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John R. Royer

Research Interests:

Soft matter, suspensions, colloidal synthesis, shaped colloids, confocal imaging, rheology

Dynamics of Shaped Colloids:

Though there has been significant progress understanding colloidal suspensions of isotropic, spherical particles, relatively little is known about how particle shape or directional interactions influence the suspension dynamics. We use a novel synthesis technique first described in Rossi et al, Soft Matter 2010 to create bulk quantities of mono-disperse cubes, ellipsoids and peanut-shaped particles. The TEM image below shows an example of one of these cubic colloids.

TEM image of a hollow, silica cube

In collaboration with Dan Blair at Georgetown University, we use 3D confocal-rheology to characterize the dynamics of these shaped particles under shear. Using depletion we can induce attractive interactions between the cube faces, allowing us to examine how anisotropic, directional interactions influence the shear-induced diffusion and shear-induced aggregation of these particles. This work is part of a larger effort within the Polymers and Complex Fluids group to address the rheology and stability of protein solutions, and is part of the NIST Bio-manufacturing initiative.

For information about my previous research on granular materials at the University of Chicago and NYU, see my personal web page.

John R. Royer, Ph. D.

Position:

Physicist
Materials Science and Engineering Division
Polymers and Complex Fluids Group

Employment History:

2012-present: NRC postdoc, Materials Science and Engineering Division, NIST

2009-2012: postdoc, Center for Soft Matter Research, New York University

Education:

Ph. D., Physics, University of Chicago, 2009

B.S., Physics, University of California, Santa Barbara, 2004

Contact

Phone: 301-975-6847
Email: john.royer@nist.gov