Research Areas: Complex Fluids, Colloids and Emulsions, Self Assembly of Amphiphilic Molecules, Micro and Nanofluidics, Protein Interactions, Nanomaterials.

Brief Description of Research:
New methods for fabricating microfluidic and nanofluidic channels provide opportunities for studying and modeling transport phenomena in very small channels, comparable with those of colloidal and biomolecular dimensions. At this length scales the channel size becomes comparable to the typical range of the interactions (electrostatic, van der Waals, etc.) creating a range of new effects and phenomena. As a part of our research effort we study the fundamental laws that govern the transport of fluid, current and dissolved analytes in small micro and nanochannels in order to quantitatively model and optimize a variety of practical applications like biomolecular separation and analysis.

Another research direction is fabrication and characterization of two dimensional arrays of ordered protein molecules on a solid substrate. A particularly interesting protein is ferritin which has a mineral (iron oxide) core. A successful ordering of these molecules in regular layers allows obtaining a two dimensional array of metal clusters. The protein shells can be easily removed by controlled pyrolysis leaving an array of metal oxide clusters. These clusters could be further reduced into metal iron. The magnetic properties of such ordered metal nanocluster arrays present a substantial fundamental interest and are also of great practical importance. A possible application is fabrication of high density magnetic memory devices.

Understanding the relationship between microscopic (particle interactions) and macroscopic (phase behavior, stability and dynamics) of complex fluids and dispersions is one of the major goals of modern colloid science. At the same time it is extremely important for a wide variety of chemical engineering and bioengineering applications as emulsion processing, controlled assembly of nanocolloids, protein phase stability both in vivo and ex vivo, new materials. The particular focus of our research in this area is on the effect of the droplet deformability on the stability and interactions of emulsion droplets, the role of the counterions on the self assembly of surfactant molecules as well as on the interaction and phase behavior of biomolecules.