Nature of Temperature-Induced Phase Transitions in Secondary Organic Aerosol Particles.

ABSTRACT: This study investigates how changes in temperature affect the secondary organic aerosol (SOA) phase state. SOA was formed by α-pinene ozonolysis in an atmospheric simulation chamber at temperatures (T₀) in the range of 257-283 K at RH₀ < 20%. After more than 14 h of SOA aging, one or more heating and cooling ramps were performed. Upon heating, we observe that the onset of evaporative SOA shrinkage is delayed by up to ∼20 K relative to T₀. Our observations are supported by aerosol dynamics and kinetic multilayer model simulations, relating observed changes to an effectively reversible temperature- and SOA-composition-dependent phase transition from solid glassy to semisolid. We demonstrate that the SOA content of highly oxygenated organic molec

SUBMITTER: Jensen LN 

PROVIDER: S-EPMC12631989 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature