Chemical Engineering
 

E. James Davis
Professor Emeritus of Chemical Engineering

Contact Information

303A Benson Hall
Box 351750
Seattle, WA 98195-1750		 Phone: 206-543-0298, 206-543-2250
Fax: 206-543-3778
E-mail: davis@cheme.washington.edu

Education

B.S., Gonzaga University, 1956.
Ph.D., University of Washington, 1960.

Research Interests

Microchemical Processes, Colloid and Aerosol Physics and Chemistry, Electrokinetics, Elastic and Inelastic Light Scattering Applied to Atmospheric Pollution

Solid particulate matter and liquid droplets in the micrometer and submicrometer size range are encountered as atmospheric pollutants, are useful for the production of high-purity materials, and are both desirable and undesirable products of the chemical industry. Much of the research involves the use of the electrodynamic balance (EDB) or "picobalance" to perform precise measurements of the physical and chemical properties of such small particles. Current research includes the study of gas-solid reactions associated with the removal of sulfur dioxide from stack gases, gas-liquid reactions for the production of high-purity microspheres which can be used as ceramic precursors or in electronic devices, measurement of the small forces which become dominant in the microgravity environment of outer space, and rate processes associated with atmospheric processes such as evaporation and condensation and gas-particulate chemical reactions. Special facilities are available for a wide variety of chemical, physical, optical, and thermal measurements.

Microparticle Spectroscopy

Gas-solid and gas-droplet chemical reactions are being studied by levitating single microparticles in the superposed ac and dc electrical fields of the EDB. The particle is held in one or more laser beams, and Raman spectroscopy (inelastic scattering) and elastic light scattering are used to follow the changes in the chemical bonds as reaction proceeds. Bioaerosols are of particular current interest. The difficulty associated with chemically characterizing them is the strong fluorescence that masks the Raman effect.

Microgravity Processes

The production of high-purity microparticles via containerless processing and the forces exerted on such particles are being studied using single particle techniques. A vacuum EDB is being used to study such phenomena in the continuum and noncontinuum transport process regimes.

Selected Recent Publications

Johnson, T.J. and Davis, E.J., Experimental Data and Theoretical Predictions for the Rate of Electrophoretic Clarification of Colloidal Suspensions. Environ. Sci Technol. 34:1806-1812 (2000).

Zheng, F., Qu, X. and Davis, E.J. Electrodynamic Balance with Octopole Double-Ring Electrodes for Three-dimensional Force Compensation. Rev. Sci. Instrum. 72:3380-3385 (2001).

Zhu, J.H., Zheng, F., Laucks, M.L. and Davis, E.J. Mass Transfer from an Oscillating Microdroplet. J. Colloid Interface Sci. 249:351-358 (2002).

Davis, E.J. and Schweiger, G. The Airborne Microparticle. Springer Verlag, Heidelberg, 833 pages, 2002.

Chen, B.H., Laucks, M.L., and Davis, E.J. Carbon Dioxide Uptake by Hydrated Lime Aerosol Particles. Aerosol Sci. Technol. 38:588-597 (2004).

Sengupta, A., Laucks, M.L., Dildine, N., Drapala, E., and Davis, E.J. Bioaerosol Characterization by Surface-Enhanced Raman Spectroscopy (SERS). J. Aerosol Sci., 36:651-664 (2005).

Sengupta, A., Laucks, M.L., and Davis, E.J., Surface-Enhanced Raman Spectroscopy of Bacteria and Pollen. Appl. Spectrosc., 59:1016-1023 (2005).

Laucks, M.L., Sengupta, A., Junge, K., Davis, E.J., and Swanson, B.D., Comparison of Psychrophilic Arctic Sea-Ice Bacteria and Common Mesophylic Bacteria Using Surface-Enhanced Raman Spectroscopy. Appl. Spectrosc. 59:1222-1228 (2005).

Go to link Recent M.S. Theses
Go to link Recent Ph.D. Dissertations