Chemical Engineering, MIT
77 Massachusetts Ave.
Cambridge, MA 02139
B.S. Chemical Engineering, Cornell University, 2006
are an important class of soft materials that are found throughout nature
and in industrial products such as paints, consumer products, cosmetics,
and drilling fluids. They typically consist of a suspension of colloidal
particles that undergoes dynamical arrest through the formation of a
fractal-like network. The arrested microstructure gives rise to unique
rheological properties, such as viscoelasticity, yield stress, shear
banding, etc. An example of an important gel-forming material is an
aqueous dispersion of the discotic synthetic clay Laponite®, often used as a rheological
modifier in industrial applications. I study the mechanical properties
of this material at macroscopic scales using bulk rheology. Additionally,
I use microrheology techniques to probe the local, microscale rheology
during gelation. These methods involve tracking the motion of
embedded probe particles subject to thermal agitation (via multiple
particle tracking microrheology) or active forces (with a magnetic tweezer).
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Typical trajectories of a Brownian probe particle
diffusing in an aqueous Laponite® dispersion at
various age times.
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Single-pole magnetic tweezer setup for studying nonlinear rheological properties at the microscopic scale (design c/o Jan Lammerding).
I am co-advised by Professor
Gareth H. McKinley in the Department of Mechanical
Other research interests:
Polymer Rheology and Dynamics
Soft Glassy Materials
Magnetorheological (MR) Suspensions
Articles: J.P. Rich, G.H. McKinley, P.S. Doyle, "Size-dependence of Microprobe Dynamics
During Gelation of a Discotic Colloidal Clay," Journal of Rheology, 55, 273-299, (2011). pdf
J.P. Rich, J. Lammerding, G.H. McKinley, P.S. Doyle, "Nonlinear microrheology of a thixotropic colloidal clay using a magnetic tweezer," Soft Matter, in preparation.
J. P. Rich, P. S. Doyle, G. H. McKinley, “Rheological characterization of a discotic colloidal clay at bulk and microscopic scales”, 13th IACIS International Conference on Surface and Colloid Science and the 83rd ACS Colloid & Surface Science Symposium: Colloid Rheology and Microrheology Session, (June 2009, New York, NY).
J. P. Rich, G. H. McKinley, P. S. Doyle, “Rheological characterization of a discotic colloidal clay at bulk and microscopic scales”, The Society of Rheology 81st Annual Meeting: Gels, Glasses and Jammed Systems Session, (October 2009, Madison, WI).
J. P. Rich, J. Lammerding, G. H. McKinley, P. S. Doyle, “Micro-scale nonlinear viscoelasticity of an aging colloidal gel using a magnetic tweezer”, AIChE Annual Meeting: Engineering Sciences and Fundamentals Group, Fluid Mechanics Area, Complex-Fluid and Bio-Fluid Dynamics Session, (November 2010, Salt Lake City, UT).
Upcoming: J. P. Rich, P. S. Doyle, G. H. McKinley, “Field-responsive rheology of magnetorheological suspensions in an aging, yield-stress matrix fluid”, 7th Annual European Rheology Conference (May 2011, Suzdal, Russia).
National Defense Science and Engineering Graduate Fellowship
ACS Petroleum Research Fund