March 30, 2023
Heather C. Allen to present H. H. King Lecture in Chemistry
Heather C. Allen, Dow professor of chemistry at The Ohio State University, will deliver the H. H. King Lecture in Chemistry beginning at 1:05 p.m. Thursday, April 6, in 4 King Hall.
Her seminar title is "Informing Ocean and Atmospheric Aerosol Chemistry: Interfacial Organization, Hydration, Binding, and Electric Fields at Aqueous Surfaces."
Abstract: We investigate ions and lipids at liquid surfaces to better understand their complexation and speciation to then inform on atmospheric aerosol, cloud and marine surface processes to ultimately impact climate model outcomes. The underlying driving forces for surface activity of bare aqueous surfaces with salts such as magnesium, calcium and sodium chlorides are one class that is explored. Research will be presented on the aqueous salt surfaces revealing surface propensity of hydrated ions and ion pairs that dominate the interfacial response in addition to interfacial hydration studies of calcium/magnesium-fatty acid surface complexation. Interfacial electric field measurements using surface potentiometry with radioactive Americium, second harmonic generation and vibrating plate methods will be presented as well as data from surface tensiometry, Brewster angle microscopy, vibrational sum frequency generation and infrared reflection absorption spectroscopy to provide clarity on surface acidity, ionization state, ion-lipid and ion-ion speciation, and thermodynamic stability of aqueous films. Allen will also mention the newest work in her lab that integrates machine learning methods with ocean sampling.