Martin IedemaSenior Research Scientist, WR Wiley Environmental Molecular Sciences Laboratory, Interface Spectroscopy/Diffraction
http://emslbios.pnl.gov/id/iedema_mj Updated: November 25, 1997
Current Activities and Projects
Ongoing work focuses on the chemistry and physics of water and aqueous solutions at vacuum-and organic solvent interfaces. Novel experiments are conducted using a low-energy ion deposition source. Diffusion behavior of the deposited ions is monitored as the sculpted films are heated and the ions encounter the embedded interfaces. We create "sandwich" films with molecular layer precision on a substrate, starting typically with an organic solvent thin film, followed by water, on top of which we deposit more solvent, then depositing the low-energy ions. The solvation of the ions as the ions traverse the sandwich during heating produces readily measured effects. These effects lead to insights into the potential energy wells and barriers that exist for ions in solution, important in aqueous solution chemistry in the environment, ion transport in biological cell membranes, and separation chemistry in zeolites.
We are also actively pursuing development of an atmospheric aerosol analysis system. We collect aerosols ranging in size from 2.5 microns in diameter to 0.2 microns with fine time resolution and store them for individual chemical and size analysis by Scanning Electron Microscopy, Secondary Ion Mass Spectrometry, and other techniques. The field collector can be used at both stationary locations and in airplane monitoring flights. We hope to characterize the chemistry of this important class (PM2.5) of particulate matter. We also have developed personal samplers for use in population studies, or where the larger sampler is too bulky.
Solvation/transport, amorphous solids, aerosol characterization, astrophysical ice.
M.S. Material Science and Engineering, Washington State University, 1999.
B.S. Physics, Astronomy, University of Southern California, 1988.