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Seminar:ÌýNonlinear Electrophoresis of Colloidal Particles

Speaker:ÌýAditya Khair, Professor of Chemical Engineering, Carnegie Mellon University

Host:ÌýAnkur Gupta

Seminar Abstract
The past decade has witnessed a surge of interest in nonlinear electrophoresis of charged colloidal particles in aqueous electrolytes. Here, the word "nonlinear" refers to the fact that the ratio of the electrophoretic speed of the particle to the magnitude of the applied electric field—the electrophoretic mobility—is not independent of field strength. This is in stark contrast to the vast majority of work on (linear) colloidal electrophoresis over the last century, where the mobility is assumed to be a material property dependent only on the particle-electrolyte combination. In this talk, KhairÌýwill first review various experimental measurements of the field-dependent mobility. He will then discuss theoretical approaches to predicting the nonlinear mobility, including asymptotic schemes in the common thin-Debye-layer limit and our own recent computations via direct numerical simulation of the full electrokinetic equations. Khair will conclude with suggestions for future work in this evolving area of colloid science.

Biosketch
Aditya Khair is a professor of chemical engineering at Carnegie Mellon University (CMU). He obtained an MEng in chemical engineering from Imperial College London in 2001. He received a certificate of advanced study in mathematics from the University of Cambridge in 2002. Later that year, he began a PhDÌýin chemical engineering at the California Institute of Technology, under the supervision of John Brady. In 2007 he began a postdoc at UC Santa Barbara, working with Todd Squires. In 2010 he joined CMU. Khair'sÌýresearch utilizes applied mathematical techniques to investigate problems in fluid mechanics, rheology, colloid science, electrokineticsÌýand electrochemistry. His work has been recognized by the AES Electrophoresis Society Mid-Career Award; Metzner Early Career Award from the Society of Rheology; the Camille Dreyfus Teacher-Scholar Award; the NSF CAREER Award; the Charles Kaufmann Foundation New Investigator Research Grant; and the Frenkiel Award of the APS Division of Fluid Dynamics.

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