Abstract View
Influence of Salt Identity on the Size Dependent Morphology of Aerosol Particles
MIRIAM FREEDMAN, Emily-Jean Ott, Penn State University
Abstract Number: 333
Working Group: Aerosol Chemistry
Abstract
Heterogeneous and multiphase chemistry are impacted by particle morphology. The internal structure of a particle depends on phase transitions and can change based on particle size. We have previously found that aerosol particles that undergo liquid-liquid phase separation have a size-dependent morphology, where the transition to two phases is inhibited in small particles. In this work, we investigate the influence of the identity of the salt on the size dependence. The ions NH4+, Na+, SO42-, HSO4-, and Cl- were investigated along with the two organic compounds, 2,5-hexanediol and diethylmalonic acid. A strong dependence of the size dependence on the cations is found with no dependence on the anion. We explain our results in terms of the hardness of the cation, where the harder cation (Na+) results in phase separation down to smaller sizes while the softer cation (NH4+) leads to an inhibition of phase separation at larger sizes. Our results have implications for understanding the differences between the morphology of sea spray and continental aerosol, which will impact the heterogeneous and multiphase morphology of these species.