Watching Molecules Orient in the Stern Layer

The orientation of molecules near a surface is interesting not only from a fundamental viewpoint, but also for controlling chemical reactivity and surface engineering properties. Using a surface potential, we control the orientation of a zwitterionic benzene derivative, and follow this orientation with broadband IR/narrowband visible sum frequency spectroscopy. Another interesting system we study via SFG is the interface formed when water meets a methyl-terminated hydrophobic surface. For this system, SFG results are compared to our group's measurements using ellipsometry and neutron reflectivity techniques.