Research Interests

Electrokinetic Phenomena
Movement of particles and fluids by electric fields in conducting or partially conducting liquids. We study complex particles (nonuniformly charged), for example, hetero-aggregates, crystalline particles, polyelectrolytes; and electroosmotic flows driven by electric fields in confined spaces with patterned surfaces, with applications to microfluidics and colloid patterning on demand at pixel level.

Electrophoretic Deposition
Particle interactions on electrodes in dc and ac electric fields. We study two-particle interactions resulting from particle-generated electroosmotic flows near the electrode and electrodynamic flow caused by electrolyte polarization near the electrode.

Bubble Coalescence on Surfaces
Bubbles on heated or cooled surfaces interact over large length scales because of thermocapillary flows about their surfaces. Bubbles come together on hot surfaces and separate on cold surfaces. Our studies focus on the dynamics of two bubbles on surfaces.

Tissue Engineering
Working with collaborators in biology, we are developing synthetic constructs to mimic tissues and study the transport of growth factors and other macromolecules in these constructs. Our main interest is in the combined effects of diffusion, convection and adsorption/desorption on the spatial and temporal distribution of growth factors.

Related Site: Colloids, Polymers, and Surfaces Program

Representative Publications

"Electrophoresis of Complex and Interacting Particles," Interfacial Electrokinetics and Electrophoresis, A. V. Delgado, editor, Marcel Dekker, pp. 147-172 (2001) (with D. Velegol and Y. Solomentsev).

"Aggregation Dynamics for Two Particles during Electrophoretic Deposition at Steady Fields," Langmuir, 16, 9208-9216 (2000) (with Y. Solomentsev, S.A. Guelcher and M. Bevan).

"Two-Particle Dynamics on an Electrode in ac Electric Fields," Advances in Colloid & Interface Science 96, 131 - 142 (2002) (with J. Kim, S. Guelcher and S. Garoff).

"Solvent Effects on the Permeability of Membrane Supported Gels," Industrial & Engineering Chemistry Research 41, 464-472 (2002) (with K. Buehler).

"Partitioning and Diffusion of Proteins and Linear Polymers in Polyacrylamide Gels," Biophys. J. 70, 1505 (1996) (with J. Tong).