scholarly journals Secondary brown carbon formation via the dicarbonyl imine pathway: nitrogen heterocycle formation and synergistic effects

2016 ◽  
Vol 18 (27) ◽  
pp. 18353-18364 ◽  
Author(s):  
C. J. Kampf ◽  
A. Filippi ◽  
C. Zuth ◽  
T. Hoffmann ◽  
T. Opatz
Keyword(s):  
Synergistic Effects ◽  
Nitrogen Heterocycles ◽  
Nitrogen Heterocycle ◽  
Carbon Formation ◽  
Brown Carbon ◽  
Reaction Systems

We observe nitrogen heterocycles to be common secondary brown carbon chromophores formed by dicarbonylsviathe imine pathway, and synergistic effects in mixed dicarbonyl reaction systems.

scholarly journals Aging of atmospheric aerosols and the role of iron in catalyzing brown carbon formation

2021 ◽  
Author(s):  
Hind A. A. Al-Abadleh
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Atmospheric Aerosols ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Atmospheric Oxidation ◽  
Carbon Formation ◽  
Brown Carbon ◽  
Volatile Organic

Extensive research has been done on the processes that lead to the formation of secondary organic aerosol (SOA) including atmospheric oxidation of volatile organic compounds (VOCs) from biogenic and anthropogenic...

scholarly journals Modeling of Carbonyl/Ammonium Sulfate Aqueous Brown Carbon Chemistry via UV/Vis Spectral Decomposition

Atmosphere ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 358 ◽  
Author(s):  
Mengjie Fan ◽  
Shiqing Ma ◽  
Nahin Ferdousi ◽  
Ziwei Dai ◽  
Joseph L. Woo
Keyword(s):  
Climate Forcing ◽  
Reaction Products ◽  
Brown Carbon ◽  
Reaction Systems ◽  
Reaction Rate Constants ◽  
Kinetic Information ◽  
First Order Kinetics ◽  
Aggregate Effect ◽  
Light Absorbance

The proper characterization of aqueous brown carbon (BrC) species, their formation, and their light absorbance properties is critical to understanding the aggregate effect that they have on overall atmospheric aerosol climate forcing. The contribution of dark chemistry secondary organic aerosol (SOA) products from carbonyl-containing organic compounds (CVOCs) to overall aqueous aerosol optical properties is expected to be significant. However, the multiple, parallel pathways that take place within CVOC reaction systems and the differing chromophoricity of individual products complicates the ability to reliably model the chemical kinetics taking place. Here, we proposed an alternative method of representing UV-visible absorbance spectra as a composite of Gaussian lineshape functions to infer kinetic information. Multiple numbers of curves and different CVOC/ammonium reaction systems were compared. A model using three fitted Gaussian curves with magnitudes following first-order kinetics achieved an accuracy within 65.5% in the 205–300-nm range across multiple organic types and solution aging times. Asymmetrical peaks that occurred in low-200-nm wavelengths were decomposed into two overlapping Gaussian curves, which may have been attributable to different functional groups or families of reaction products. Component curves within overall spectra exhibited different dynamics, implying that the utilization of absorbance at a single reference wavelength to infer reaction rate constants may result in misrepresentative kinetics for these systems.

Effect of Relative Humidity on Secondary Brown Carbon Formation in Aqueous Droplets

2020 ◽  
Vol 54 (20) ◽  
pp. 13207-13216
Author(s):  
Nethmi Y. Kasthuriarachchi ◽  
Laura-Hélèna Rivellini ◽  
Xi Chen ◽  
Yong Jie Li ◽  
Alex K. Y. Lee
Keyword(s):  
Relative Humidity ◽  
Carbon Formation ◽  
Brown Carbon

Brown Carbon Formation from Nighttime Chemistry of Unsaturated Heterocyclic Volatile Organic Compounds

2019 ◽  
Vol 6 (3) ◽  
pp. 184-190 ◽  
Author(s):  
Huanhuan Jiang ◽  
Alexander L. Frie ◽  
Avi Lavi ◽  
Jin Y. Chen ◽  
Haofei Zhang ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Carbon Formation ◽  
Brown Carbon ◽  
Nighttime Chemistry ◽  
Volatile Organic

scholarly journals Glyoxal's impact on dry ammonium salts: fast and reversible surface aerosol browning

2020 ◽  
Author(s):  
David O. De Haan ◽  
Lelia N. Hawkins ◽  
Kevin Jansen ◽  
Hannah G. Welsh ◽  
Raunak Pednekar ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Gas Phase ◽  
Ammonium Sulfate ◽  
Aerosol Particles ◽  
Ammonium Salts ◽  
Carbon Formation ◽  
Cloud Droplets ◽  
Brown Carbon ◽  
Dicarbonyl Compounds ◽  
Dry Conditions

Abstract. Alpha-dicarbonyl compounds are believed to form brown carbon in the atmosphere via reactions with ammonium sulfate (AS) in cloud droplets and aqueous aerosol particles. In this work, brown carbon formation in AS and other aerosol particles was quantified as a function of relative humidity (RH) during exposure to gas-phase glyoxal (GX) in chamber experiments. Under dry conditions (RH 

scholarly journals Brown carbon formation from ketoaldehydes of biogenic monoterpenes

2013 ◽  
Vol 165 ◽  
pp. 473 ◽  
Author(s):  
Tran B. Nguyen ◽  
Alexander Laskin ◽  
Julia Laskin ◽  
Sergey A. Nizkorodov
Keyword(s):  
Carbon Formation ◽  
Brown Carbon

scholarly journals Aqueous-Phase Brown Carbon Formation from Aromatic Precursors under Sunlight Conditions

Atmosphere ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 131 ◽  
Author(s):  
Kristijan Vidović ◽  
Ana Kroflič ◽  
Martin Šala ◽  
Irena Grgić
Keyword(s):  
Aqueous Phase ◽  
Concentration Ratio ◽  
Organic Aerosol ◽  
Chemical Processes ◽  
Reaction Products ◽  
Carbon Formation ◽  
Primary Reaction ◽  
Brown Carbon ◽  
Kinetics Of ◽  
Characteristic Mass

At present, there are still numerous unresolved questions concerning the mechanisms of light-absorbing organic aerosol (brown carbon, BrC) formation in the atmosphere. Moreover, there is growing evidence that chemical processes in the atmospheric aqueous phase can be important. In this work, we investigate the aqueous-phase formation of BrC from 3-methylcatechol (3MC) under simulated sunlight conditions. The influence of different HNO2/NO2− concentrations on the kinetics of 3MC degradation and BrC formation was investigated. Under illumination, the degradation of 3MC is faster (k2nd(global) = 0.075 M−1·s−1) in comparison to its degradation in the dark under the same solution conditions (k2nd = 0.032 M−1·s−1). On the other hand, the yield of the main two products of the dark reaction (3-methyl-5-nitrocatechol, 3M5NC, and 3-methyl-4-nitrocatechol, 3M4NC) is low, suggesting different degradation pathways of 3MC in the sunlight. Besides the known primary reaction products with distinct absorption at 350 nm, second-generation products responsible for the absorption above 400 nm (e.g., hydroxy-3-methyl-5-nitrocatechol, 3M5NC-OH, and the oxidative cleavage products of 3M4NC) were also confirmed in the reaction mixture. The characteristic mass absorption coefficient (MAC) values were found to increase with the increase of NO2−/3MC concentration ratio (at the concentration ratio of 50, MAC is greater than 4 m2·g−1 at 350 nm) and decrease with the increasing wavelength, which is characteristic for BrC. Yet, in the dark, roughly 50% more BrC is produced at comparable solution conditions (in terms of MAC values). Our findings reveal that the aqueous-phase processing of 3MC in the presence of HNO2/NO2−, both under the sunlight and in the dark, may significantly contribute to secondary organic aerosol (SOA) light absorption.

No evidence for brown carbon formation in ambient particles undergoing atmospherically relevant drying

2020 ◽  
Vol 22 (2) ◽  
pp. 442-450 ◽  
Author(s):  
Vikram Pratap ◽  
Michael A. Battaglia ◽  
Annmarie G. Carlton ◽  
Christopher J. Hennigan
Keyword(s):  
Carbon Formation ◽  
Brown Carbon ◽  
Ambient Particles ◽  
First Time ◽  
Atmospherically Relevant

This work shows, for the first time, that brown carbon formation is not observed in ambient particles undergoing drying.

Sign in / Sign up

Export Citation Format

Share Document