Heterogeneous Oxidation Dynamics of Atmospheric Organic Aerosols

The heterogeneous oxidation of atmospheric organic aerosols encompasses the chemical ageing processes that occur when gas-phase oxidants encounter particulate organic matter. These reactions proceed at the air–particle interface and within the particle bulk, where factors such as particle phase state, viscosity and surface morphology govern molecular diffusion and reaction rates. Oxidants including ozone, hydroxyl radicals and nitrate radicals initiate ozonolysis, hydrogen abstraction and other pathways, generating secondary products that can alter volatility, hygroscopicity and optical properties. The interplay between surface accommodation, bulk diffusion and secondary radical chemistry determines the reactive uptake coefficient and thus the atmospheric lifetime of organic constituents. Understanding these multiphase kinetics is crucial for accurate prediction of air quality, cloud formation, radiative forcing and human health impacts on regional to global scales.

Research from Nature Portfolio

Complex three-dimensional self-assembly in proxy aerosol droplets has been shown to form lyotropic phases that substantially reduce the rate of ozone uptake by creating viscous shells around reactive cores. This foundational work demonstrates that ordered nanostructures within fatty-acid-based model aerosols impart a diffusion barrier to oxidants, extending chemical lifetimes and influencing radiative and cloud-nucleating properties. Such insights highlight the importance of internal organisation in determining heterogeneous oxidation dynamics and provide a paradigm for interpreting atmospheric observations.

Heterogeneous Oxidation Dynamics of Atmospheric Organic Aerosols publication trend

The graph below shows the total number of articles in heterogeneous oxidation dynamics of atmospheric organic aerosols across all publications each year (not limited to Nature Index journals).

Technical terms

Heterogeneous oxidation: Chemical transformation of aerosol-bound organics by gas-phase oxidants at the particle interface.

Reactive uptake coefficient: Probability that a gas-phase oxidant reacting with a particle surface will lead to net chemical transformation.

Phase state: Physical form of an aerosol particle (liquid, semi-solid or glassy) affecting diffusion and reaction rates.

Multiphase kinetics: Study of chemical reactions coupled with mass transport across gas, surface and bulk phases.

Ozonolysis: Reaction of ozone with organic compounds, often cleaving carbon–carbon double bonds.

Lyotropic phase: Ordered molecular arrangement in an aqueous system induced by amphiphilic molecules and humidity.

References

1. Complex three-dimensional self-assembly in proxies for atmospheric aerosols. Nature Communications (2017).
2. A numerical compass for experiment design in chemical kinetics and molecular property estimation. Journal of Cheminformatics (2024).
3. Accelerating models for multiphase chemical kinetics through machine learning with polynomial chaos expansion and neural networks. Geoscientific Model Development (2023).
4. Acoustic levitation combined with laboratory-based small-angle X-ray scattering (SAXS) to probe changes in crystallinity and molecular organisation. RSC Advances (2024).