The Effect of Chain Length on Physiochemical Properties of Perfluoroalkyl Pollutants at the Surface of Water
Abstract
The role that man-made pollutants play in environment is a large uncertainty for scientists trying to predict the impacts of future climate change. Perfluoroalkyl substances persist in the environment and require intense heat and pressure to breakdown, even if we completely banned them now, these pollutants will still be around longer than any of us. This study looks at how perfluoroalkyl substances at two different chain lengths accumulate at the surface and how this changes with different pH. Sum Frequency Generation Spectroscopy is used to probe only the surface of a sample, in this case we used 1 mM solutions of Octanoic Acid, Decanoic Acid, Perfluorooctanoic Acid, and Perfluorodecanoic Acid. Fluoronation was shown to increase the SFG signal which correlates to more ordering of water molecules at the surface. We conducted surface tension measurements on all 4 of these molecules to determine their surface pKa.
The Effect of Chain Length on Physiochemical Properties of Perfluoroalkyl Pollutants at the Surface of Water
The role that man-made pollutants play in environment is a large uncertainty for scientists trying to predict the impacts of future climate change. Perfluoroalkyl substances persist in the environment and require intense heat and pressure to breakdown, even if we completely banned them now, these pollutants will still be around longer than any of us. This study looks at how perfluoroalkyl substances at two different chain lengths accumulate at the surface and how this changes with different pH. Sum Frequency Generation Spectroscopy is used to probe only the surface of a sample, in this case we used 1 mM solutions of Octanoic Acid, Decanoic Acid, Perfluorooctanoic Acid, and Perfluorodecanoic Acid. Fluoronation was shown to increase the SFG signal which correlates to more ordering of water molecules at the surface. We conducted surface tension measurements on all 4 of these molecules to determine their surface pKa.