Surface-selective vibrational sum frequency generation spectroscopy is applied to probe the hydrogen bond network at the air-water interface by (1) using the line shape of the free OD stretch mode as a localized surface probe and (2) using the rotational relaxation of a small probe molecule (propiolic acid). The first approach reports on the H-bond strength at the interface via isotopic dilution dependence of the free OD line shape. The second provides dynamical information on the relaxation time scales of the surface H-bond network from the analysis of polarization-selected line shapes of the probe molecule. Together, these two measurements provide a more consistent picture of the H-bonding near the surface, and how it compares with the bulk water H-bonds.

Structure and dynamics of hydrogen bonds at the air-water interface

244th National Meeting (2012)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.