45840-G5
Experiments for Improved Understanding of the Wetting of Polar Liquids
During the past year we have made significant progress towards our overarching goals of understanding the wetting of polar liquids on solid surfaces.
PRF funds, to date, have specifically been used (1) to purchase supplies and rent gases for our measurements of wetting angles and surface adsorption as a function of pressure,(2) to support one undergraduate student Ergys Subashi, (3) to provide a partial month of summer support for myself, (4) to cover publication costs, and (5) to purchase a Nanoscope reflectometer suitable for quick film thickness determinations.
As a direct result of the funding provided by our PRF starter grant, we published two research articles this year, including a Physical Review Letter. Also as result of successes funded by starter grant, we gained substantial NSF funding (NSF MRI #0821292) for the purchase of a spectroscopic ellipsometer ($137 000) that will significantly aid in our studies of prewetting transitions of water and other fluids at elevated temperatures where the temperature-sensitivity of quartz microbalances make them not as suitable for our studies.
The chief personnel outcomes of the past year were the graduation of Ergys Subashi, who is now pursuing graduate study at Duke University's Biophysics Program. A second student Kenneth Osborne formally joined the PhD. physics program at WPI and is presently working in prof. Garcia's lab on this project. He is being supported on a teaching assistantship.
Although we intend to continue soon our water contact angle measurements to higher temperatures, we have at present paused while Kenneth Osborne writes up the results obtained thus far for his M.S. thesis. This gives us a chance to to understand the experimental results, which appear to indicated unexpectedly-large contributions due electrostatic double-layer forces. We also made quartz microbalance measurements of the adsorption of nitrous oxide on gold and are analyzing those results.
