Office Phone: 301 405-4311
Office Address: 3130B
 Group Website



  • Ph.D. Chemical Engineering, University of California, Los Angeles 1986
  • M.S. Chemical Engineering, University of California, Los Angeles 1981
  • B.S. Biochemistry, University of California, Los Angeles 1979

Professional Experience

  • 2003- Professor, University of Maryland Director of the UMCP/NIST Co-Laboratory on Nanomanufacturing and Metrology
  • 2002-2003 Professor, University of Minnesota, Minneapolis Director, Center for Nanoenergetics Research
  • 1998 – 2002 Mayhugh Associate Professor, University of Minnesota, Minneapolis,
  • 1992- 1998 Leader, Reacting Flows Group, National Institute of Standards and Technology, Gaithersburg, MD
  • 1986 – 1992 Staff Scientist, National Institute of Standards and Technology, Gaithersburg, MD

       Associate Editor – Journal of Nanoparticle Research (from September 2006)

       Editorial Advisory Board – Journal of Aerosol Science and Technology (1996-2005)                                                                –                                                                – International Journal of Chemical Kinetics (1998-2002)

Research Interests

  • NanoParticle Science and Technology.
  • Cluster and nanoparticle materials synthesis.
  • Materials under extreme conditions and materials for energy science.
  • Ion mobility and mass spectrometry.

A complete list of publications (365) and PDF links can be found at:

for Federal/DOD users:


Probing Nanomaterials in Energy, Health and the Environment

Our research is multidisciplinary and the publications with PDF files can be found at -click on publications link.

The focus of our research is two fold:

a. Developing analytic tools (Nanolytics) to study nanoparticles and nanowires.

b. Developing using aerosol methods new materials with application to energy and nanomedicine.

c. Nanomaterials under extreme conditions.

Our focus is on aerosol based methods for which we have developed new mass-spectrometric and ion-mobility methods to probe the behavior and function of nanoparticles and nanowires. A typical question for example might be, can we determine in solution what the surface coating is on a nanoparticle, and how is it oriented? These questions are relevant to material contaminants in the environment, the use of nanoparticles in medicine, and the manufacturing of nanomaterials in industry.

Recently we have developed electrospray atmospheric ion mobility spectrometry to measure the orientation of SAM’s on nanoparticles and their binding energy as a function of particle size. This work has been extended to determine the orientation of DNA binding on Au NP’s which have relevance to medicinal chemistry. We have also used these methods to study the reaction kinetics of solar driven chemistry to generate hydrogen from water, in which we obtain the detailed behavior of how nanoparticles react as a function of particle size. We have applied these methods very recently to probe the interaction of proteins, in particular antibody binding to nanoparticles, and there aggregation behavior in solution. We have a strong collaboration with atmospheric sciences in which we make and characterize environmental aerosols relevant to global climate change. In particular we are now trying to understand how coated soot particles might enhance absorption of sunlight and lead to enhanced global warming.

We have a unique T-Jump Time-of-Flight mass spectrometer to measure ultrafast condensed state reactions at higher temperatures with a resolution of 100 s. Here we are able to see how nanoparticles react under extreme conditions. We also have built a new molecular beam mass spectrometer to enable measurement of radial species during catalysis.






Electrospray mobilty spectrometer and spectrum of bare vs DNA coated Au

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