While many factors drive the planet’s warming, it is believed that atmospheric aerosols, on average, can help offset this through cloud formation. The surface of the aerosol controls its ability to take up water and form clouds, which change the surface albedo of the planet and increase the solar radiation reflected back into space. Sea spray aerosols, in particular, are ubiquitous particles in our atmosphere that become suspended in the air when ocean waves break. These aerosols contain a plethora of organic and inorganic compounds, including but not limited to free amino acids and salt ions. Amino acids have been shown to impact aerosol hygroscopicity, and we have observed that salt concentrations and pH levels affect their surface activity in sea spray. Leucine, a surface-active amino acid known to be prevalent in sea spray, was used to better understand how salts are responsible for stabilizing organics at the interface. Steered all-atom molecular dynamics (MD) simulations were combined with umbrella sampling to construct potential of mean force (PMF) plots, enabling us to investigate the surface propensity of leucine at different protonation states. Surface tension measurements agreed with computational findings and gave quantitative data on the surface activity of leucine. This work can ultimately be extended to incorporate more complex biomolecules including peptides and proteins.

Surface activity of leucine in sea spray aerosols: Insights from a combined computational and experimental approach

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

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