Molecular insights into the composition, sources, and aging of atmospheric brown carbon

Chemical Society Reviews, Год журнала: 2025, Номер unknown

Опубликована: Янв. 1, 2025

The light-absorbing chemical components of atmospheric organic aerosols are commonly referred to as Brown Carbon (BrC), reflecting the characteristic yellowish brown appearance aerosol.

Язык: Английский

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Intermolecular Interactions Enhance the Light Absorption of a Methoxyphenol Constituent of Biomass Burning Emissions

ACS ES&T Air, Год журнала: 2025, Номер 2(3), С. 406 - 415

Опубликована: Фев. 27, 2025

Brown carbon (BrC) components of biomass burning organic aerosol (BBOA) absorb sunlight at visible wavelengths. However, it is not clear whether the total light absorption this BrC simply sum contributions individual or can bind noncovalently to give additional through charge transfer. Here, intermolecular interactions between guaiacol and quinones (1,4-benzoquinone 1,4-naphthoquinone) were identified in proxies nonpolar, water-insoluble phase BBOA, using UV-vis spectroscopy. Guaiacol its derivatives are some most abundant emissions smoldering coniferous species. Enhanced occurred instantaneously upon mixing colorless with either quinone n-heptane did increase time, contrast absorbance changes that would be expected for a covalent product. This enhancement decreased by about 25% as temperature increased from 303 323 K, consistent exothermic association complexes, yielding enthalpies complexation -13.3 ± 0.6 -12.3 0.4 kJ mol-1 benzoquinone naphthoquinone, respectively. Enhancement was also observed gas-liquid partitioning into thin films guaiacol, example, thickness 20 μm. multiphase processing, mimicking liquid produced comparable moderately absorbing other sources, suggestive atmospheric relevance these interactions.

Язык: Английский

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Molecular Insights into Gas–Particle Partitioning and Viscosity of Atmospheric Brown Carbon

Environmental Science & Technology, Год журнала: 2024, Номер unknown

Опубликована: Окт. 4, 2024

Biomass burning organic aerosol (BBOA), containing brown carbon chromophores, plays a critical role in atmospheric chemistry and climate forcing. However, the effects of evaporation on BBOA volatility viscosity under different environmental conditions remain poorly understood. This study focuses molecular characterization laboratory-generated proxies from wood pyrolysis emissions. The initial mixture, "pyrolysis oil (PO

Язык: Английский

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The phase state and viscosity of organic aerosol and related impacts on atmospheric physicochemical processes: A review

Atmospheric Environment, Год журнала: 2024, Номер 343, С. 120985 - 120985

Опубликована: Дек. 11, 2024

Язык: Английский

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Multiphase Processing of the Water-Soluble and Insoluble Phases of Biomass Burning Organic Aerosol

ACS ES&T Air, Год журнала: 2025, Номер unknown

Опубликована: Март 31, 2025

Biomass burning is one of the most significant sources organic aerosol in atmosphere. (BBOA) has been observed to undergo liquid–liquid phase separation (LLPS) give core–shell morphology with hydrophobic encapsulating hydrophilic phase, potentially impacting evolution light-absorbing components, i.e., brown carbon (BrC), through multiphase processes. Here, we demonstrate how processing differs between water-soluble (i.e., hydrophilic) and insoluble hydrophobic) phases BBOA terms reactive uptake ozone a coated-wall flow tube. Effects relative humidity (RH) ultraviolet (UV) irradiation were investigated. Experimental timeseries used inform simulations using multilayer kinetic modeling. Among non-irradiated thin films, coefficient was greatest for at 75% RH (3 × 10–5, corresponding diffusion BrC, DBrC, 3 10–9 cm2 s–1) least same 0% (1 DBrC 1 10–10 s–1). The water-insoluble fell these two (about 1.5 10–5), regardless RH, increased only slightly (8 s–1 9 RH). coefficients both decreased significantly after UV irradiation, consistent transition from viscous liquid solid supported by qualitative microscopy observations. Modeling oxidation primary BrC components atmosphere demonstrated, first, that LLPS may extend lifetime encapsulated species factor moderate high and, also, more than 2.5.

Язык: Английский

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Rapid Nighttime Darkening of Biomass Burning Brown Carbon by Nitrate Radicals Is Suppressed by Prior Daytime Photochemical Aging

ACS Earth and Space Chemistry, Год журнала: 2025, Номер unknown

Опубликована: Апрель 12, 2025

Язык: Английский

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Viscosity and Phase State of Wildfire Smoke Particles in the Stratosphere from Pyrocumulonimbus Events: An Initial Assessment

Environmental Science & Technology, Год журнала: 2025, Номер unknown

Опубликована: Апрель 17, 2025

Understanding the viscosity and phase state of biomass-burning organic aerosol (BBOA) from wildfires pyrocumulonimbus (pyroCb) events in stratosphere is critical for predicting their role stratospheric multiphase chemistry ozone depletion. However, BBOA under conditions, including interactions with sulfuric acid (H2SO4), remain largely unquantified. In this study, we combine laboratory data a thermodynamic model to predict conditions. Our results suggest that H2SO4-to-BBOA mass ratio 0.37─an estimated upper limit pyroCb smoke lower after two months aging─is highly viscous frequently exists glassy state. Even at higher 0.79─an nine aging─BBOA can still transition certain state, bulk reactions are suppressed, may be limited particle surfaces. We also highlight key areas future research needed better constrain its subsequent impact on ozone.

Язык: Английский

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Secondary Organic Aerosol from Biomass Burning Phenolic Compounds and Nitrate Radicals can be Highly Viscous over a Wide Relative Humidity Range

Environmental Science & Technology, Год журнала: 2024, Номер 58(49), С. 21702 - 21715

Опубликована: Ноя. 27, 2024

Biomass burning events, including wildfires, can emit large amounts of phenolic compounds such as guaiacol. These undergo oxidation by nitrate radicals (NO

Язык: Английский

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Biomass burning organic aerosol (BBOA) from wildfires has multiple phases and is more viscous than laboratory generated BBOA

Опубликована: Май 7, 2024

Biomass burning organic aerosol (BBOA) is a major contributor to in the atmosphere. The impacts of BBOA on climate and health depend strongly their physicochemical properties, including viscosity phase behaviour (number types phases); these relationships chemistry, are not yet fully characterized. We collected field samples during 2021 British Columbia wildfire season constrain at range relative humidities, compared them laboratory generated made from smoldering pine wood. Particles all exhibited two-phased with higher polarity hydrophilic core lower hydrophobic shell. used poke-flow technique estimate particles. found that both phases had viscosities >10 8 Pa s humidities up 50%, which more viscous than any or proxies previously measured. Aerosol mass spectrometry showed were oxidized those lab, likely explanation for viscosity. two high have implications how should be treated atmospheric models

Язык: Английский

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Species-specific effect of particle viscosity and particle-phase reactions on the formation of secondary organic aerosol

The Science of The Total Environment, Год журнала: 2024, Номер 950, С. 175207 - 175207

Опубликована: Авг. 2, 2024

Язык: Английский

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