Kyriakos Papadopoulos
 |
Professor BS: Columbia University, 1978 Department of Chemical & Biomolecular Engineering Research WebsiteBiographical Sketch Research Interests Teaching Publications <<< back to Faculty |
Biographical Sketch
Our research focuses on some of the phenomena that are important in the separation, transport and reaction processes of particulate systems, with emphasis on environmental, drug delivery and lubricant-technology applications. In a mixed-waste suspension, colloids may aggregate and form particles that are large enough to settle (coagulation), or they may resist aggregation thus averting solid-liquid separation (colloid stability). The process of coagulation is routinely used for concentrating waste in industrial water effluents. In our research, we have proposed theoretical models to explain coagulation processes in concentrated suspensions and have conducted experiments to confront the theory. We have also studied suspension and emulsion flows through sand-packed beds, in order to determine the conditions that favor particle aggregation and droplet coalescence and entrapment, or conversely, their free passage through the porous network of the soil.
In soil bioremediation processes, bacteria metabolize toxic organic compounds. We have investigated the transport of such bacteria through capillaries that are models for soil pores. In our capillaries, which may have a diameter of only three microns, we have visually studied the random motility and chemotactic behavior of E. Coli. We have observed and reported a new mode of motility in capillaries, the unidirectional motility, which explains how bacteria can access contaminants in soil pores with dimensions that are comparable to their own.
Our capillary video-microscopy technique has allowed the discovery of a phenomenon in the stability of double emulsions, or emulsion liquid membranes, used for separations, drug delivery, red-blood-cell substitutes etc. A new finding was that the internal droplets inside a suspended globule (say small water droplets inside a big oil droplet, which is in turn suspended in water) do not coalesce among themselves. Some of our recent studies include (i) the development of an optical-microscopic test for improving marine-engine lubrication oils, (ii) the transport of water through liquid-emulsion membranes under osmotic pressure for drug delivery applications, and (iii) the role of humic substances in colloid-facilitated transport.
300 Lindy Boggs Center, Tulane University, New Orleans, LA 70118 504-865-5772 ph, 504-865-6744 fax chemeng@tulane.edu