Past Event: Soft Surfaces and Aqueous Interfaces: An Insightful View of Molecular and Ion Organization

Join Yale Chemistry for a Physical Chemistry Seminar with Dr. Heather Allen, Dow Professor and Ohio State Distinguished Scholar, from Ohio State University. Summary: Biomembrane ion transfer, lung surfactant, interfacial chemistry of materials, energy applications, ocean to marine aerosol concentration enrichments, geochemical weathering, environmental phosphate capture, and cloud droplet-surface electric fields provide the motivation for studies of interfacial ion pairing, binding, and surface prevalence and organization of molecules at interfaces. Ion surface activity and organization at aqueous soft interfaces has been controversial for decades although there is growing but limited consensus. Here interfacial structure and the interfacial driving forces are presented using vibrational sum frequency generation spectroscopy (VSFG), second harmonic generation (SHG), Brewster angle microscopy (BAM), surface potential, surface tension, polarized Raman, and reflection absorption infrared. Some focus is on Fe(III), Al(III), Ca(II), Mg(II), saccharides, water, and solvents such as glycerol and propylene carbonate, and surface pKa of surfactant lipids and fatty acids. Binding mechanisms and ion surface activity are not necessarily correlated in that the driving forces of electrostatics and nonspecific dispersion compete with surprising outcomes. Applied electric field data from aqueous interfaces is also explored to reveal inherent aqueous surface acidity at neutral solution-phase pH.

More information on the Allen Group can be found here: https://research.cbc.osu.edu/allen.697/

Faculty Host: Professor Elsa Yan.

This seminar can be viewed online at this link: https://yale.hosted.panopto.com/Panopto/Pages/Viewer.aspx?id=54c8fd18-e195-4aa2-a8ea-b17e00e23fcf