Secondary Brown Carbon Formed by a Microreactor of a Levitated Aqueous Fe (III) Droplet with Fumaric Acid.

ABSTRACT: This study investigates the influence of fumaric acid on the optical and microphysical properties of aqueous FeCl₃ microdroplets and how aging affects them. This process replicates a pathway for brown carbon (BrC) formation in the atmosphere. The experiment combines a Paul electrodynamic trap (PET), which captures a single particle, and a dual-wavelength cavity ring-down spectroscopy (CRDS) system. Initially, measurements were conducted under controlled humidity cycling, obtaining the particle phase function at a 532 nm wavelength. Retrievals reveal an irreversible increase in particle radius and complex refractive index (m _λ = n _λ + ik·_λ) after a dehydration-hydration cycle. The second part involves measuring a single partic

SUBMITTER: Sanchez-Jimenez G 

PROVIDER: S-EPMC12784408 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature